Method for generating harq-ack codebook in wireless communication system and device using same

ABSTRACT

Disclosed is a base station in a wireless communication system. Each base station in wireless communication comprises: a communication module; and a processor. The processor generates a hybrid automatic repeat request (HARQ)-ACK codebook comprising one or more bits and indicating whether or not reception of a channel or signal is successful, and transmits the HARQ-ACK codebook to the base station.

TECHNICAL FIELD

The present disclosure relates to a wireless communication system.Specifically, the present disclosure relates to a method for generatinga HARQ-ACK codebook in a wireless communication system, and a deviceusing the same.

BACKGROUND ART

After commercialization of 4th generation (4G) communication system, inorder to meet the increasing demand for wireless data traffic, effortsare being made to develop new 5th generation (5G) communication systems.The 5G communication system is called as a beyond 4G networkcommunication system, a post LTE system, or a new radio (NR) system. Inorder to achieve a high data transfer rate, 5G communication systemsinclude systems operated using the millimeter wave (mmWave) band of 6GHz or more, and include a communication system operated using afrequency band of 6 GHz or less in terms of ensuring coverage so thatimplementations in base stations and terminals are under consideration.

A 3rd generation partnership project (3GPP) NR system enhances spectralefficiency of a network and enables a communication provider to providemore data and voice services over a given bandwidth. Accordingly, the3GPP NR system is designed to meet the demands for high-speed data andmedia transmission in addition to supports for large volumes of voice.The advantages of the NR system are to have a higher throughput and alower latency in an identical platform, support for frequency divisionduplex (FDD) and time division duplex (TDD), and a low operation costwith an enhanced end-user environment and a simple architecture.

For more efficient data processing, dynamic TDD of the NR system may usea method for varying the number of orthogonal frequency divisionmultiplexing (OFDM) symbols that may be used in an uplink and downlinkaccording to data traffic directions of cell users. For example, whenthe downlink traffic of the cell is larger than the uplink traffic, thebase station may allocate a plurality of downlink OFDM symbols to a slot(or subframe). Information about the slot configuration should betransmitted to the terminals.

In order to alleviate the path loss of radio waves and increase thetransmission distance of radio waves in the mmWave band, in 5Gcommunication systems, beamforming, massive multiple input/output(massive MIMO), full dimensional MIMO (FD-MIMO), array antenna, analogbeam-forming, hybrid beamforming that combines analog beamforming anddigital beamforming, and large scale antenna technologies are discussed.In addition, for network improvement of the system, in the 5Gcommunication system, technology developments related to evolved smallcells, advanced small cells, cloud radio access network (cloud RAN),ultra-dense network, device to device communication (D2D), vehicle toeverything communication (V2X), wireless backhaul, non-terrestrialnetwork communication (NTN), moving network, cooperative communication,coordinated multi-points (CoMP), interference cancellation, and the likeare being made. In addition, in the 5G system, hybrid FSK and QAMmodulation (FQAM) and sliding window superposition coding (SWSC), whichare advanced coding modulation (ACM) schemes, and filter bankmulti-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparsecode multiple access (SCMA), which are advanced connectivitytechnologies, are being developed.

Meanwhile, in a human-centric connection network where humans generateand consume information, the Internet has evolved into the Internet ofThings (IoT) network, which exchanges information among distributedcomponents such as objects. Internet of Everything (IoE) technology,which combines IoT technology with big data processing technologythrough connection with cloud servers, is also emerging. In order toimplement IoT, technology elements such as sensing technology,wired/wireless communication and network infrastructure, serviceinterface technology, and security technology are required, so that inrecent years, technologies such as sensor network, machine to machine(M2M), and machine type communication (MTC) have been studied forconnection between objects. In the IoT environment, an intelligentinternet technology (IT) service that collects and analyzes datagenerated from connected objects to create new value in human life canbe provided. Through the fusion and mixture of existing informationtechnology (IT) and various industries, IoT can be applied to fieldssuch as smart home, smart building, smart city, smart car or connectedcar, smart grid, healthcare, smart home appliance, and advanced medicalservice.

Accordingly, various attempts have been made to apply the 5Gcommunication system to the IoT network. For example, technologies suchas a sensor network, a machine to machine (M2M), and a machine typecommunication (MTC) are implemented by techniques such as beamforming,MIMO, and array antennas. The application of the cloud RAN as the bigdata processing technology described above is an example of the fusionof 5G technology and IoT technology. Generally, a mobile communicationsystem has been developed to provide voice service while ensuring theuser's activity.

However, the mobile communication system is gradually expanding not onlythe voice but also the data service, and now it has developed to theextent of providing high-speed data service. However, in a mobilecommunication system in which services are currently being provided, amore advanced mobile communication system is required due to a shortagephenomenon of resources and a high-speed service demand of users.

DETAILED DESCRIPTION OF THE INVENTION Technical Problem

In one aspect, an embodiment of the present disclosure provides a methodfor efficiently generating a HARQ-ACK codebook in a wirelesscommunication system, and a device therefor.

Technical Solution

A user equipment in a wireless communication system according to anembodiment of the present disclosure includes: a communication module;and a processor configured to control the communication module. Theprocessor is configured to: generate a hybrid automatic repeat request(HARQ)-ACK codebook including one or mode bits indicating whether achannel or signal is successfully received, and transmit the HARQ-ACKcodebook to a base station.

The HARQ-ACK codebook may be a dynamic HARQ-ACK codebook in which thenumber of bits of the HARQ-ACK codebook is determined based oninformation signaled by a physical downlink control channel (PDCCH). Theprocessor may transmit the HARQ-ACK codebook via a physical uplinkcontrol channel (PDCCH) transmitted in a resource indicated by the lastPDCCH. The last PDCCH may be a PDCCH last received by the user equipmentamong a signal indicating whether reception is successful or not or aPDCCH scheduling a channel through the HARQ-ACK codebook.

The processor may determine a PDCCH corresponding to the last PDCCHamong the plurality of PDCCHs, based on a symbol on which each of theplurality of PDCCHs is received. When it is not possible to determine aPDCCH corresponding to the last PDCCH among the plurality of PDCCHs,based on a symbol on which each of the plurality of PDCCHs is received,the processor may determine the PDCCH corresponding to the last PDCCHamong the plurality of PDCCHs, based on a cell index of a cell in whicheach of the plurality of PDCCHs is received.

When it is not possible to determine the PDCCH corresponding to the lastPDCCH among the plurality of PDCCHs, based on a symbol at which each ofthe plurality of PDCCHs is received and a cell index of a cell whereeach of the plurality of PDCCHs is received, the processor may determinethe PDCCH corresponding to the last PDCCH among the plurality of PDCCHs,based on an index of a physical resource block (PRB) to which each ofthe plurality of PDCCHs is mapped.

When it is not possible to determine a PDCCH corresponding to the lastPDCCH among the plurality of PDCCHs, based on a symbol at which each ofthe plurality of PDCCHs is received and a cell index of a cell whereeach of the plurality of PDCCHs is received, the processor may determinethe PDCCH corresponding to the last PDCCH among the plurality of PDCCHs,based on an index of a control resource set (CORESET) to which each ofthe plurality of PDCCHs is mapped.

The processor may determine the PDCCH corresponding to the last PDCCHamong the plurality of PDCCHs, based on a symbol on which each of theplurality of PDCCHs is received. When the start symbols of the pluralityof PDCCHs are the same and the last symbols of the plurality of PDCCHsare the same, the resources for PUCCH transmission indicated by theplurality of PDCCHs may be the same.

The HARQ_ACK codebook may be a semi-static HARQ_ACK codebook configuredto indicate which channel or signal is successfully received by thenumber of bits of the HARQ-ACK codebook and each bit of the HARQ-ACKcodebook, based on radio resource control (RRC) signaling. When the userequipment receives an SPS PDSCH release PDCCH for releasing asemi-persistent scheduling (SPS) physical downlink shared channel(PDSCH) configured for the user equipment, the processor may insert abit indicating HARQ-ACK for the SPS PDSCH release PDCCH instead of a bitindicating HARQ-ACK for the SPS PDSCH released by the SPS PDSCH releasephysical downlink shared channel (PDCCH) in the HARQ-ACK codebook.

When the SPS PDSCH release PDCCH releases a plurality of SPS PDSCHreception configurations configured for the user equipment, theprocessor may insert a bit indicating HARQ-ACK for the SPS PDSCH releasePDCCH in the HARQ-ACK codebook instead of a bit indicating HARQ-ACK forthe SPS PDSCH of one of the plurality of SPS PDSCH receptionconfigurations.

When the SPS PDSCH release PDCCH releases a plurality of SPS PDSCHreception configurations configured for the user equipment, theprocessor may insert a bit indicating HARQ-ACK for the SPS PDSCH releasePDCCH in the HARQ-ACK codebook instead of a bit indicating HARQ-ACK foreach SPS PDSCH in the plurality of SPS PDSCH reception configurations.

The HARQ-ACK codebook may be a semi-static HARQ-ACK codebook that isconfigured based on radio resource control (RRC) signaling in which thenumber of bits of the HARQ-ACK codebook and each bit of the HARQ-ACKcodebook indicate which channel or signal reception is successful. Whenthe user equipment receives an SPS PDSCH release PDCCH for releasing asemi-persistent scheduling (SPS) physical downlink shared channel(PDSCH) configured for the user equipment, the processor may insert abit indicating HARQ-ACK for the SPS PDSCH release PDCCH in acorresponding bit in the HARQ-ACK for transmission in a resourceindicated by a time-domain resource assignment (TDRA) field of the SPSPDSCH release PDCCH in the HARQ-ACK codebook.

The processor may expect that the base station does not schedule achannel or signal to which HARQ-ACK is to be transmitted through theHARQ-ACK codebook in the resource indicated by the TDRA field of the SPSPDSCH release PDCCH.

The HARQ-ACK codebook may be a dynamic HARQ-ACK codebook in which thenumber of bits of the HARQ-ACK codebook is determined based oninformation signaled by a physical downlink control channel (PDCCH).When the user equipment receives the SPS PDSCH of a semi-persistentscheduling (SPS) physical downlink shared channel (PDSCH) configured forthe user equipment, the processor may add 1 bit indicating HARQ-ACK forthe SPS PDSCH to the HARQ-ACK codebook.

When the user equipment is configured to receive a plurality of SPSPDSCHs, the processor may determine the location of the HARQ-ACK foreach SPS PDSCH in the HARQ-ACK codebook, based on the indexes of each ofthe plurality of SPS PDSCH reception configurations. Each of theplurality of SPS PDSCH release PDCCHs corresponds to each of theplurality of SPS PDSCH reception configurations.

When a plurality of SPS PDSCH reception configurations are configured inthe user equipment, the processor may determine the location of theHARQ-ACK for each SPS PDSCH in the plurality of SPS PDSCH receptionconfigurations, based on the index of each of the plurality of SPS PDSCHreception configurations and the time resource in which each SPS PDSCHis transmitted in the plurality of SPS PDSCH reception configurations,in the HARQ-ACK codebook.

When a plurality of SPS PDSCH reception configurations are configured inthe user equipment, the processor may determine the location of theHARQ-ACK for the SPS PDSCH of each of the plurality of SPS PDSCHreception configurations in the HARQ-ACK codebook, based on the HARQprocess number of each of the plurality of SPS PDSCH receptionconfigurations.

The HARQ-ACK codebook may be a dynamic HARQ-ACK codebook in which thenumber of bits of the HARQ-ACK codebook is determined based oninformation signaled by a physical downlink control channel (PDCCH).When a resource scheduled for a semi-persistent scheduling (SPS)physical downlink shared channel (PDSCH) configured for the userequipment and a resource scheduled for a PDSCH scheduled by the PDCCHoverlap, the processor may insert a bit indicating HARQ-ACK for a PDSCHscheduled by the PDCCH in the HARQ-ACK codebook instead of a bitindicating HARQ-ACK for the SPS PDSCH.

When a resource in which a plurality of SPS PDSCHs scheduled for theuser equipment are scheduled and a resource in which a PDSCH scheduledby the PDCCH is scheduled overlap, the processor may insert a bitindicating HARQ-ACK for the PDSCH scheduled by the PDCCH in the HARQ-ACKcodebook instead of a bit indicating HARQ-ACK for one of the pluralityof SPS PDSCHs.

One of the plurality of SPS PDSCHs may be determined based on a timefrequency resource through which each of the plurality of SPS PDSCHs istransmitted.

One of the plurality of SPS PDSCHs may be determined based on the indexof each of the plurality of SPS PDSCHs.

One of the plurality of SPS PDSCHs may be determined based on a HARQprocess number corresponding to each of the plurality of SPS PDSCHs.

Advantageous Effects

An embodiment of the present disclosure provides a method forefficiently receiving a physical control channel in a wirelesscommunication system, and a device using the same.

Advantageous effects obtainable from the present disclosure are notlimited to the above-mentioned advantageous effects, and otheradvantageous effects not mentioned herein will be clearly understoodfrom the following description by those skilled in the art to which thepresent disclosure pertains.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless frame structure used in awireless communication system;

FIG. 2 illustrates an example of a downlink (DL)/uplink (UL) slotstructure in a wireless communication system;

FIG. 3 is a diagram for explaining a physical channel used in a 3GPPsystem and a typical signal transmission method using the physicalchannel;

FIG. 4 illustrates an SS/PBCH block for initial cell access in a 3GPP NRsystem;

FIGS. 5A and 5B illustrate a procedure for transmitting controlinformation and a control channel in a 3GPP NR system;

FIG. 6 illustrates a control resource set (CORESET) in which a physicaldownlink control channel (PUCCH) may be transmitted in a 3GPP NR system;

FIG. 7 illustrates a method for configuring a PDCCH search space in a3GPP NR system;

FIG. 8 is a conceptual diagram illustrating carrier aggregation;

FIG. 9 is a diagram for explaining signal carrier communication andmultiple carrier communication;

FIG. 10 is a diagram showing an example in which a cross carrierscheduling technique is applied;

FIG. 11 is a block diagram showing the configurations of a UE and a basestation according to an embodiment of the present disclosure.

FIGS. 12A and 12B illustrate that a UE generates a dynamic HARQ-ACKcodebook and transmits the same to a base station according to anembodiment of the present disclosure;

FIG. 13 illustrates a case where one PDCCH is received from a resourcemapped by a plurality of CORESETs;

FIG. 14 illustrates a method for a UE to transmit HARQ-ACK for an SPSPDSCH release PDCCH using a semi-static HARQ-ACK codebook according toan embodiment of the present disclosure'

FIG. 15 illustrates a time interval in which a base station can transmitan SPS PDSCH release PDCCH according to an embodiment of the presentdisclosure;

FIG. 16 illustrates a case where a plurality of bits indicating HARQ-ACKfor each of a plurality of SPS PDSCHs having the same index are includedin the dynamic HARQ-ACK codebook together according to an embodiment ofthe present disclosure; and

FIG. 17 illustrates a method for a UE to generate a dynamic HARQ-ACKcodebook when an SPS PDSCH-scheduled resource and a DG PDSCH-scheduledresource overlap according to an embodiment of the present disclosure.

MODE FOR CARRYING OUT THE INVENTION

Terms used in the specification adopt general terms which are currentlywidely used as possible by considering functions in the presentdisclosure, but the terms may be changed depending on an intention ofthose skilled in the art, customs, and emergence of new technology.Further, in a specific case, there is a term arbitrarily selected by anapplicant and in this case, a meaning thereof will be described in acorresponding description part of the present disclosure. Accordingly,it intends to be revealed that a term used in the specification shouldbe analyzed based on not just a name of the term but a substantialmeaning of the term and contents throughout the specification.

Throughout this specification and the claims that follow, when it isdescribed that an element is “connected” to another element, the elementmay be “directly connected” to the other element or “electricallyconnected” to the other element through a third element. Further, unlessexplicitly described to the contrary, the word “comprise” will beunderstood to imply the inclusion of stated elements but not theexclusion of any other elements unless otherwise stated. Moreover,limitations such as “more than or equal to” or “less than or equal to”based on a specific threshold may be appropriately substituted with“more than” or “less than”, respectively, in some exemplary embodiments.

The following technology may be used in various wireless access systems,such as code division multiple access (CDMA), frequency divisionmultiple access (FDMA), time division multiple access (TDMA), orthogonalfrequency division multiple access (OFDMA), single carrier-FDMA(SC-FDMA), and the like. The CDMA may be implemented by a wirelesstechnology such as universal terrestrial radio access (UTRA) orCDMA2000. The TDMA may be implemented by a wireless technology such asglobal system for mobile communications (GSM)/general packet radioservice (GPRS)/enhanced data rates for GSM evolution (EDGE). The OFDMAmay be implemented by a wireless technology such as IEEE 802.11(Wi-Fi),IEEE 802.16(WiMAX), IEEE 802-20, evolved UTRA (E-UTRA), and the like.The UTRA is a part of a universal mobile telecommunication system(UMTS). 3rd generation partnership project (3GPP) long term evolution(LTE) is a part of an evolved UMTS (E-UMTS) using evolved-UMTSterrestrial radio access (E-UTRA) and LTE-advanced (A) is an evolvedversion of the 3GPP LTE. 3GPP new radio (NR) is a system designedseparately from LTE/LTE-A, and is a system for supporting enhancedmobile broadband (eMBB), ultra-reliable and low latency communication(URLLC), and massive machine type communication (mMTC) services, whichare requirements of IMT-2020. For the clear description, 3GPP NR ismainly described, but the technical idea of the present disclosure isnot limited thereto.

Unless otherwise specified in this specification, a base station mayrefer to a next generation node B (gNB) as defined in 3GPP NR.Furthermore, unless otherwise specified, a terminal may refer to a userequipment (UE). Hereinafter, in order to facilitate understanding of thedescription, each content is separately divided into embodiments anddescribed, but each of the embodiments may be used in combination witheach other. In the present disclosure, the configuration of the UE mayindicate configuration by the base station. Specifically, the basestation may transmit a channel or signal to the UE to configured anoperation of the UE or a parameter value used in a wirelesscommunication system.

FIG. 1 illustrates an example of a wireless frame structure used in awireless communication system.

Referring to FIG. 1 , the wireless frame (or radio frame) used in the3GPP NR system may have a length of 10 ms (Δf max Nf/100)*Tc). Inaddition, the wireless frame includes 10 subframes (SFs) having equalsizes. Herein, Δf max=480*103 Hz, Nf=4096, Tc=1/(Δfref*Nf,ref),Δfref=15*103 Hz, and Nf,ref=2048. Numbers from 0 to 9 may berespectively allocated to 10 subframes within one wireless frame. Eachsubframe has a length of 1 ms and may include one or more slotsaccording to a subcarrier spacing. More specifically, in the 3GPP NRsystem, the subcarrier spacing that may be used is 15*2μ kHz, and μ canhave a value of μ=0, 1, 2, 3, 4 as subcarrier spacing configuration.That is, 15 kHz, 30 kHz, 60 kHz, 120 kHz and 240 kHz may be used forsubcarrier spacing. One subframe having a length of 1 ms may include 2μslots. In this case, the length of each slot is 2-μ ms. Numbers from 0to 2μ−1 may be respectively allocated to 2μ slots within one subframe.In addition, numbers from 0 to 10*2μ−1 may be respectively allocated toslots within one subframe. The time resource may be distinguished by atleast one of a wireless frame number (also referred to as a wirelessframe index), a subframe number (also referred to as a subframe number),and a slot number (or a slot index).

FIG. 2 illustrates an example of a downlink (DL)/uplink (UL) slotstructure in a wireless communication system. In particular, FIG. 2shows the structure of the resource grid of the 3GPP NR system.

There is one resource grid per antenna port. Referring to FIG. 2 , aslot includes a plurality of orthogonal frequency division multiplexing(OFDM) symbols in a time domain and includes a plurality of resourceblocks (RBs) in a frequency domain. An OFDM symbol also means one symbolsection. Unless otherwise specified, OFDM symbols may be referred tosimply as symbols. One RB includes 12 consecutive subcarriers in thefrequency domain. Referring to FIG. 2 , a signal transmitted from eachslot may be represented by a resource grid including Nsize,μgrid,x*NRBscsubcarriers, and Nslotsymb OFDM symbols. Here, x=DL when the signal is aDL signal, and x=UL when the signal is an UL signal. Nsize,μgrid,xrepresents the number of resource blocks (RBs) according to thesubcarrier spacing constituent μ (x is DL or UL), and Nslotsymbrepresents the number of OFDM symbols in a slot. NRBsc is the number ofsubcarriers constituting one RB and NRBsc=12. An OFDM symbol may bereferred to as a cyclic shift OFDM (CP-OFDM) symbol or a discreteFourier transform spread OFDM (DFT-s-OFDM) symbol according to amultiple access scheme.

The number of OFDM symbols included in one slot may vary according tothe length of a cyclic prefix (CP). For example, in the case of a normalCP, one slot includes 14 OFDM symbols, but in the case of an extendedCP, one slot may include 12 OFDM symbols. In a specific embodiment, theextended CP can only be used at 60 kHz subcarrier spacing. In FIG. 2 ,for convenience of description, one slot is configured with 14 OFDMsymbols by way of example, but embodiments of the present disclosure maybe applied in a similar manner to a slot having a different number ofOFDM symbols. Referring to FIG. 2 , each OFDM symbol includesNsize,μgrid,x*NRBsc subcarriers in the frequency domain. The type ofsubcarrier may be divided into a data subcarrier for data transmission,a reference signal subcarrier for transmission of a reference signal,and a guard band. The carrier frequency is also referred to as thecenter frequency (fc).

One RB may be defined by NRBsc (e. g., 12) consecutive subcarriers inthe frequency domain. For reference, a resource configured with one OFDMsymbol and one subcarrier may be referred to as a resource element (RE)or a tone. Therefore, one RB can be configured with Nslotsymb*NRBscresource elements. Each resource element in the resource grid can beuniquely defined by a pair of indexes (k, l) in one slot. k may be anindex assigned from 0 to Nsize,μgrid, x*NRBsc−1 in the frequency domain,and l may be an index assigned from 0 to Nslotsymb−1 in the time domain.

In order for the UE to receive a signal from the base station or totransmit a signal to the base station, the time/frequency of the UE maybe synchronized with the time/frequency of the base station. This isbecause when the base station and the UE are synchronized, the UE candetermine the time and frequency parameters necessary for demodulatingthe DL signal and transmitting the UL signal at the correct time.

Each symbol of a radio frame used in a time division duplex (TDD) or anunpaired spectrum may be configured with at least one of a DL symbol, anUL symbol, and a flexible symbol. A radio frame used as a DL carrier ina frequency division duplex (FDD) or a paired spectrum may be configuredwith a DL symbol or a flexible symbol, and a radio frame used as a ULcarrier may be configured with a UL symbol or a flexible symbol. In theDL symbol, DL transmission is possible, but UL transmission isimpossible. In the UL symbol, UL transmission is possible, but DLtransmission is impossible. The flexible symbol may be determined to beused as a DL or an UL according to a signal.

Information on the type of each symbol, i.e., information representingany one of DL symbols, UL symbols, and flexible symbols, may beconfigured with a cell-specific or common radio resource control (RRC)signal. In addition, information on the type of each symbol mayadditionally be configured with a UE-specific or dedicated RRC signal.The base station informs, by using cell-specific RRC signals, i) theperiod of cell-specific slot configuration, ii) the number of slots withonly DL symbols from the beginning of the period of cell-specific slotconfiguration, iii) the number of DL symbols from the first symbol ofthe slot immediately following the slot with only DL symbols, iv) thenumber of slots with only UL symbols from the end of the period of cellspecific slot configuration, and v) the number of UL symbols from thelast symbol of the slot immediately before the slot with only the ULsymbol. Here, symbols not configured with any one of a UL symbol and aDL symbol are flexible symbols.

When the information on the symbol type is configured with theUE-specific RRC signal, the base station may signal whether the flexiblesymbol is a DL symbol or an UL symbol in the cell-specific RRC signal.In this case, the UE-specific RRC signal can not change a DL symbol or aUL symbol configured with the cell-specific RRC signal into anothersymbol type. The UE-specific RRC signal may signal the number of DLsymbols among the Nslotsymb symbols of the corresponding slot for eachslot, and the number of UL symbols among the Nslotsymb symbols of thecorresponding slot. In this case, the DL symbol of the slot may becontinuously configured with the first symbol to the i-th symbol of theslot. In addition, the UL symbol of the slot may be continuouslyconfigured with the j-th symbol to the last symbol of the slot (wherei<j). In the slot, symbols not configured with any one of a UL symboland a DL symbol are flexible symbols.

FIG. 3 is a diagram for explaining a physical channel used in a 3GPPsystem (e.g., NR) and a typical signal transmission method using thephysical channel.

If the power of the UE is turned on or the UE camps on a new cell, theUE performs an initial cell search (S101). Specifically, the UE maysynchronize with the BS in the initial cell search. For this, the UE mayreceive a primary synchronization signal (PSS) and a secondarysynchronization signal (SSS) from the base station to synchronize withthe base station, and obtain information such as a cell ID. Thereafter,the UE can receive the physical broadcast channel from the base stationand obtain the broadcast information in the cell.

Upon completion of the initial cell search, the UE receives a physicaldownlink shared channel (PDSCH) according to the physical downlinkcontrol channel (PDCCH) and information in the PDCCH, so that the UE canobtain more specific system information than the system informationobtained through the initial cell search (S102). Here, the systeminformation received by the UE is cell-common system information for theUE to properly operate at the physical layer in Radio Resource Control(RRC), and is referred to as remaining system information (RSMI) orsystem information block (SIB) 1.

When the UE initially accesses the base station or does not have radioresources for signal transmission (when the UE is in RRC_IDLE mode), theUE may perform a random access procedure on the base station (operationsS103 to S106). First, the UE can transmit a preamble through a physicalrandom access channel (PRACH) (S103) and receive a response message forthe preamble from the base station through the PDCCH and thecorresponding PDSCH (S104). When a valid random access response messageis received by the UE, the UE transmits data including the identifier ofthe UE and the like to the base station through a physical uplink sharedchannel (PUSCH) indicated by the UL grant transmitted through the PDCCHfrom the base station (S105). Next, the UE waits for reception of thePDCCH as an indication of the base station for collision resolution. Ifthe UE successfully receives the PDCCH through the identifier of the UE(S106), the random access process is terminated. During the randomaccess process, the UE may obtain UE-specific system informationnecessary for the UE to properly operate at the physical layer in theRRC layer. When the UE obtains UE-specific system information from theRRC layer, the UE enters the RRC_CONNECTED mode.

The RRC layer is used for message generation and management for controlbetween a UE and a radio access network (RAN). More specifically, in theRRC layer, the base station and the UE may perform broadcasting of cellsystem information, delivery management of paging messages, mobilitymanagement and handover, measurement report and control thereof, UEcapability management, and storage management including existingmanagement necessary for all UEs in the cell. In general, since theupdate of the signal (hereinafter, referred to as RRC signal)transmitted from the RRC layer is longer than the transmission/receptionperiod (i.e., transmission time interval, TTI) in the physical layer,the RRC signal may be maintained unchanged for a long period.

After the above-described procedure, the UE receives PDCCH/PDSCH (S107)and transmits a physical uplink shared channel (PUSCH)/physical uplinkcontrol channel (PUCCH) (S108) as a general UL/DL signal transmissionprocedure. In particular, the UE may receive downlink controlinformation (DCI) through the PDCCH. The DCI may include controlinformation such as resource allocation information for the UE. Also,the format of the DCI may vary depending on the intended use. The uplinkcontrol information (UCI) that the UE transmits to the base stationthrough UL includes a DL/UL ACK/NACK signal, a channel quality indicator(CQI), a precoding matrix index (PMI), a rank indicator (RI), and thelike. Here, the CQI, PMI, and RI may be included in channel stateinformation (CSI). In the 3GPP NR system, the UE may transmit controlinformation such as HARQ-ACK and CSI described above through the PUSCHand/or PUCCH.

FIG. 4 illustrates an SS/PBCH block for initial cell access in a 3GPP NRsystem.

When the power is turned on or wanting to access a new cell, the UE mayobtain time and frequency synchronization with the cell and perform aninitial cell search procedure. The UE may detect a physical cellidentity NcellID of the cell during a cell search procedure. For this,the UE may receive a synchronization signal, for example, a primarysynchronization signal (PSS) and a secondary synchronization signal(SSS), from a base station, and synchronize with the base station. Inthis case, the UE can obtain information such as a cell identity (ID).

Referring to FIG. 4A, a synchronization signal (SS) will be described inmore detail. The synchronization signal can be classified into PSS andSSS. The PSS may be used to obtain time domain synchronization and/orfrequency domain synchronization, such as OFDM symbol synchronizationand slot synchronization. The SSS can be used to obtain framesynchronization and cell group ID. Referring to FIG. 4A and Table 2, theSS/PBCH block can be configured with consecutive 20 RBs(=240subcarriers) in the frequency axis, and can be configured withconsecutive 4 OFDM symbols in the time axis. In this case, in theSS/PBCH block, the PSS is transmitted in the first OFDM symbol and theSSS is transmitted in the third OFDM symbol through the 56th to 182thsubcarriers. Here, the lowest subcarrier index of the SS/PBCH block isnumbered from 0. In the first OFDM symbol in which the PSS istransmitted, the base station does not transmit a signal through theremaining subcarriers, i.e., 0th to 55th and 183th to 239th subcarriers.In addition, in the third OFDM symbol in which the SSS is transmitted,the base station does not transmit a signal through 48th to 55th and183th to 191th subcarriers. The base station transmits a physicalbroadcast channel (PBCH) through the remaining RE except for the abovesignal in the SS/PBCH block.

TABLE 1 Channel OFDM symbol number l Subcarrier number k or relative tothe start relative to the start signal of an SS/PBCH block of an SS/PBCHblock PSS 0 56, 57, . . . , 182 SSS 2 56, 57, . . . , 182 Set to 0 0 0,1, . . . , 55, 183, 184, . . . , 239 2 48, 49 , . . . , 55, 183, 184, .. . , 191 PBCH 1, 3 0, 1, . . . , 239 2 0, 1, . . . , 47, 192, 193, . .. , 239 DM-RS 1, 3 0 + ν, 4 + ν, 8 + ν, . . . , 44 + ν for 2 0 + ν, 4 +ν, 8 + ν, . . . , 44 + ν PBCH 192 + ν, 196 + ν, . . . , 236 + ν

The SS allows a total of 1008 unique physical layer cell IDs to begrouped into 336 physical-layer cell-identifier groups, each groupincluding three unique identifiers, through a combination of three PSSsand SSSs, specifically, such that each physical layer cell ID is to beonly a part of one physical-layer cell-identifier group. Therefore, thephysical layer cell ID NcellID=3N(1)ID+N(2)ID can be uniquely defined bythe index N(1)ID ranging from 0 to 335 indicating a physical-layercell-identifier group and the index N(2)ID ranging from 0 to 2indicating a physical-layer identifier in the physical-layercell-identifier group. The UE may detect the PSS and identify one of thethree unique physical-layer identifiers. In addition, the UE can detectthe SSS and identify one of the 336 physical layer cell IDs associatedwith the physical-layer identifier. In this case, the sequence dPSS(n)of the PSS is as follows.

d _(PSS)(n)=1−2x(m)

m=(n+43N _(ID) ⁽²⁾)mod 127

0≤n<127

Here x(i+7)=(x(i+4)+x(i))mod 2

and is given as [x(6) x(5) x(4) x(3) x(2) x(1) x(0)]=[1 1 1 0 1 1 0].

Further, the sequence dSSS(n) of the SSS is as follows.

${{d_{SSS}(n)} = {\left\lbrack {1 - {2{x_{0}\left( {\left( {n + m_{0}} \right){mod}127} \right)}}} \right\rbrack\left\lbrack {1 - {2{x_{1}\left( {\left( {n + m_{1}} \right){mod}127} \right)}}} \right\rbrack}}\begin{matrix}{m_{0} = {{15\left\lfloor \frac{N_{ID}^{(1)}}{112} \right\rfloor} + {5N_{ID}^{(2)}}}} \\{m_{1} = {N_{ID}^{(1)}{mod}112}}\end{matrix}$ 0 ≤ n < 127x ₀(i+7)=(x ₀(i+4)+x ₀(i))mod 2

Here, x ₁(i+7)=(x ₁(i+1)+x ₁(i))mod 2

[x₀(6) x₀(5) x₀(4) x₀(3) x₀(2) x₀(1) x₀(0)]=[0 0 0 0 0 0 1]

[x₁(6) x₁(5) x₁(4) x₁(3) x₁(2) x₁(1) x₁(0)]=[0 0 0 0 0 0 1]

A radio frame with a 10 ms length may be divided into two half frameswith a 5 ms length. Referring to FIG. 4B, a description will be made ofa slot in which SS/PBCH blocks are transmitted in each half frame. Aslot in which the SS/PBCH block is transmitted may be any one of thecases A, B, C, D, and E. In the case A, the subcarrier spacing is 15 kHzand the starting time point of the SS/PBCH block is the ({2, 8}+14*n)-thsymbol. In this case, n=0 or 1 at a carrier frequency of 3 GHz or less.In addition, it may be n=0, 1, 2, 3 at carrier frequencies above 3 GHzand below 6 GHz. In the case B, the subcarrier spacing is 30 kHz and thestarting time point of the SS/PBCH block is {4, 8, 16, 20}+28*n. In thiscase, n=0 at a carrier frequency of 3 GHz or less. In addition, it maybe n=0, 1 at carrier frequencies above 3 GHz and below 6 GHz. In thecase C, the subcarrier spacing is 30 kHz and the starting time point ofthe SS/PBCH block is the ({2, 8}+14*n)-th symbol. In this case, n=0 or 1at a carrier frequency of 3 GHz or less. In addition, it may be n=0, 1,2, 3 at carrier frequencies above 3 GHz and below 6 GHz. In the case D,the subcarrier spacing is 120 kHz and the starting time point of theSS/PBCH block is the ({4, 8, 16, 20}+28*n)-th symbol. In this case, at acarrier frequency of 6 GHz or more, n=0, 1, 2, 3, 5, 6, 7, 8, 10, 11,12, 13, 15, 16, 17, 18. In the case E, the subcarrier spacing is 240 kHzand the starting time point of the SS/PBCH block is the ({8, 12, 16, 20,32, 36, 40, 44}+56*n)-th symbol. In this case, at a carrier frequency of6 GHz or more, n=0, 1, 2, 3, 5, 6, 7, 8.

FIG. 5 illustrates a procedure for transmitting control information anda control channel in a 3GPP NR system. Referring to FIG. 5A, the basestation may add a cyclic redundancy check (CRC) masked (e.g., an XORoperation) with a radio network temporary identifier (RNTI) to controlinformation (e.g., downlink control information (DCI)) (S202). The basestation may scramble the CRC with an RNTI value determined according tothe purpose/target of each control information. The common RNTI used byone or more UEs can include at least one of a system information RNTI(SI-RNTI), a paging RNTI (P-RNTI), a random access RNTI (RA-RNTI), and atransmit power control RNTI (TPC-RNTI). In addition, the UE-specificRNTI may include at least one of a cell temporary RNTI (C-RNTI), and theCS-RNTI. Thereafter, the base station may perform rate-matching (S206)according to the amount of resource(s) used for PDCCH transmission afterperforming channel encoding (e.g., polar coding) (S204). Thereafter, thebase station may multiplex the DCI(s) based on the control channelelement (CCE) based PDCCH structure (S208). In addition, the basestation may apply an additional process (S210) such as scrambling,modulation (e.g., QPSK), interleaving, and the like to the multiplexedDCI(s), and then map the DCI(s) to the resource to be transmitted. TheCCE is a basic resource unit for the PDCCH, and one CCE may include aplurality (e.g., six) of resource element groups (REGs). One REG may beconfigured with a plurality (e.g., 12) of REs. The number of CCEs usedfor one PDCCH may be defined as an aggregation level. In the 3GPP NRsystem, an aggregation level of 1, 2, 4, 8, or 16 may be used. FIG. 5Bis a diagram related to a CCE aggregation level and the multiplexing ofa PDCCH and illustrates the type of a CCE aggregation level used for onePDCCH and CCE(s) transmitted in the control area according thereto.

FIG. 6 illustrates a control resource set (CORESET) in which a physicaldownlink control channel (PUCCH) may be transmitted in a 3GPP NR system.

The CORESET is a time-frequency resource in which PDCCH, that is, acontrol signal for the UE, is transmitted. In addition, a search spaceto be described later may be mapped to one CORESET. Therefore, the UEmay monitor the time-frequency domain designated as CORESET instead ofmonitoring all frequency hands for PDCCH reception, and decode the PDCCHmapped to CORESET. The base station may configure one or more CORESETsfor each cell to the UE. The CORESET may be configured with up to threeconsecutive symbols on the time axis. In addition, the CORESET may beconfigured in units of six consecutive PRBs on the frequency axis. Inthe embodiment of FIG. 5 , CORESET#1 is configured with consecutivePRBs, and CORESET#2 and CORESET#3 are configured with discontinuousPRBs. The CORESET can be located in any symbol in the slot. For example,in the embodiment of FIG. 5 , CORESET#1 starts at the first symbol ofthe slot, CORESET#2 starts at the fifth symbol of the slot, andCORESET#9 starts at the ninth symbol of the slot.

FIG. 7 illustrates a method for setting a PUCCH search space in a 3GPPNR system.

In order to transmit the PDCCH to the UE, each CORESET may have at leastone search space. In the embodiment of the present disclosure, thesearch space is a set of all time-frequency resources (hereinafter,PDCCH candidates) through which the PDCCH of the UE is capable of beingtransmitted. The search space may include a common search space that theUE of the 3GPP NR is required to commonly search and a Terminal-specificor a UE-specific search space that a specific UE is required to search.In the common search space, UE may monitor the PDCCH that is set so thatall UEs in the cell belonging to the same base station commonly search.In addition, the UE-specific search space may be set for each UE so thatUEs monitor the PDCCH allocated to each UE at different search spaceposition according to the UE. In the case of the UE-specific searchspace, the search space between the UEs may be partially overlapped andallocated due to the limited control area in which the PDCCH may beallocated. Monitoring the PDCCH includes blind decoding for PDCCHcandidates in the search space. When the blind decoding is successful,it may be expressed that the PDCCH is (successfully) detected/receivedand when the blind decoding fails, it may be expressed that the PDCCH isnot detected/not received, or is not successfully detected/received.

For convenience of explanation, a PDCCH scrambled with a group common(GC) RNTI previously known to UEs so as to transmit DL controlinformation to the one or more UEs is referred to as a group common (GC)PDCCH or a common PDCCH. In addition, a PDCCH scrambled with aspecific-terminal RNTI that a specific UE already knows so as totransmit UL scheduling information or DL scheduling information to thespecific UE is referred to as a specific-UE PDCCH. The common PDCCH maybe included in a common search space, and the UE-specific PDCCH may beincluded in a common search space or a UE-specific PDCCH.

The base station may signal each UE or UE group through a PDCCH aboutinformation (i.e., DL Grant) related to resource allocation of a pagingchannel (PCH) and a downlink-shared channel (DL-SCH) that are atransmission channel or information (i.e., UL grant) related to resourceallocation of a uplink-shared channel (UL-SCH) and a hybrid automaticrepeat request (HARQ). The base station may transmit the PCH transportblock and the DL-SCH transport block through the PDSCH. The base stationmay transmit data excluding specific control information or specificservice data through the PDSCH. In addition, the UE may receive dataexcluding specific control information or specific service data throughthe PDSCH.

The base station may include, in the PDCCH, information on to which UE(one or a plurality of UEs) PDSCH data is transmitted and how the PDSCHdata is to be received and decoded by the corresponding UE, and transmitthe PDCCH. For example, it is assumed that the DCI transmitted on aspecific PDCCH is CRC masked with an RNTI of “A”, and the DCI indicatesthat PDSCH is allocated to a radio resource (e.g., frequency location)of “B” and indicates transmission format information (e.g., transportblock size, modulation scheme, coding information, etc.) of “C”. The UEmonitors the PDCCH using the RNTI information that the UE has. In thiscase, if there is a UE which performs blind decoding the PDCCH using the“A” RNTI, the UE receives the PDCCH, and receives the PDSCH indicated by“B” and “C” through the received PDCCH information.

Table 2 shows an embodiment of a physical uplink control channel (PUCCH)used in a wireless communication system.

TABLE 2 PUCCH format Length in OFDM symbols Number of bits 0 1-2  ≤2 14-14 ≤2 2 1-2  >2 3 4-14 >2 4 4-14 >2

PUCCH may be used to transmit the following UL control information(UCI).

-   -   Scheduling Request (SR): Information used for requesting a UL        UL-SCH resource.    -   HARQ-ACK: A Response to PDCCH (indicating DL SPS release) and/or        a response to DL transport block (TB) on PDSCH. HARQ-ACK        indicates whether information transmitted on the PDCCH or PDSCH        is received. The HARQ-ACK response includes positive ACK (simply        ACK), negative ACK (hereinafter NACK), Discontinuous        Transmission (DTX), or NACK/DTX. Here, the term HARQ-ACK is used        mixed with HARQ-ACK/NACK and ACK/NACK. In general, ACK may be        represented by bit value 1 and NACK may be represented by bit        value 0.    -   Channel State Information (CSI): Feedback information on the DL        channel. The UE generates it based on the CSI-Reference Signal        (RS) transmitted by the base station. Multiple Input Multiple        Output (MIMO)-related feedback information includes a Rank        Indicator (RI) and a Precoding Matrix Indicator (PMI). CSI can        be divided into CSI part 1 and CSI part 2 according to the        information indicated by CSI.

In the 3GPP NR system, five PUCCH formats may be used to support variousservice scenarios, various channel environments, and frame structures.

PUCCH format 0 is a format capable of transmitting 1-bit or 2-bitHARQ-ACK information or SR. PUCCH format 0 can be transmitted throughone or two OFDM symbols on the time axis and one RB on the frequencyaxis. When PUCCH format 0 is transmitted in two OFDM symbols, the samesequence to the two symbols may be transmitted through different RBs. Inthis case, the sequence may be a cyclic shift (CS) sequence from thebase sequence used for PUCCH format 0. Through this, the UE can obtain afrequency diversity gain. Specifically, the UE may determine a cyclicshift (CS) value m_(cs) according to the M_(bit) bit UCI (M_(bit)=1 or2). In addition, a sequence in which a base sequence of length 12 iscyclically shifted based on a predetermined CS value m_(cs) may bemapped to 1 OFDM symbol and 12 REs of 1 RB and transmitted. When thenumber of cyclic shifts available to the UE is 12 and M_(bit)=1, 1 bitUCI 0 and 1 may be mapped to two cyclic shifted sequences having adifference of 6 cyclic shift values, respectively. In addition, whenM_(bit)=2, 2 bits UCI 00, 01, 11, and 10 may be mapped to four cyclicshifted sequences in which the difference in cyclic shift values is 3,respectively.

PUCCH format 1 may deliver 1-bit or 2-bit HARQ-ACK information or SR.PUCCH format 1 may be transmitted through consecutive OFDM symbols onthe time axis and one PRB on the frequency axis. Here, the number ofOFDM symbols occupied by PUCCH format 1 may be one of 4 to 14. Morespecifically, UCL which is Mbit=1, may be BPSK-modulated. The UE maymodulate UCI, which is Mbit=2, with quadrature phase shift keying(QPSK). A signal is obtained by multiplying a modulated complex valuedsymbol d(0) by a sequence of length 12. In this case, the sequence maybe a base sequence used for PUCCH format 0. The UE spreads theeven-numbered OFDM symbols to which PUCCH format 1 is allocated throughthe time axis orthogonal cover code (OCC) to transmit the obtainedsignal. PUCCH format 1 determines the maximum number of different UEsmultiplexed in the one RB according to the length of the OCC to be used.A demodulation reference signal (DMRS) may be spread with OCC and mappedto the odd-numbered OFDM symbols of PUCCH format 1.

PUCCH format 2 may deliver UCI exceeding 2 bits. PUCCH format 2 may betransmitted through one or two OFDM symbols on the time axis and one ora plurality of RBs on the frequency axis. When PUCCH format 2 istransmitted in two OFDM symbols, the sequences which are transmitted indifferent RBs through the two OFDM symbols may be same each other. Here,the sequence may be a plurality of modulated complex valued symbolsd(0), . . . , d(Msymbol−1). Here, Msymbol may be Mbit/2. Through this,the UE may obtain a frequency diversity gain. More specifically, Mbitbit UCI (Mbit>2) is bit-level scrambled, QPSK modulated, and mapped toRB(s) of one or two OFDM symbol(s). Here, the number of RBs may be oneof 1 to 16.

PUCCH format 3 or PUCCH format 4 may deliver UCI exceeding 2 bits. PUCCHformat 3 or PUCCH format 4 may be transmitted through consecutive OFDMsymbols on the time axis and one PRB on the frequency axis. The numberof OFDM symbols occupied by PUCCH format 3 or PUCCH format 4 may be oneof 4 to 14. Specifically, the UE modulates Mbit bits UCI (Mbit>2) withπ/2−Binary Phase Shift Keying (BPSK) or QPSK to generate a complexvalued symbol d(0) to d(Msymb−1). Here, when using π/2−BPSK, Msymb=Mbit,and when using QPSK, Msymb=Mbit/2. The UE may not apply block-unitspreading to the PUCCH format 3. However, the UE may apply block-unitspreading to one RB (i.e., 12 subcarriers) using PreDFT-OCC of a lengthof 12 such that PUCCH format 4 may have two or four multiplexingcapacities. The UE performs transmit precoding (or DFT-precoding) on thespread signal and maps it to each RE to transmit the spread signal.

In this case, the number of RBs occupied by PUCCH format 2, PUCCH format3, or PUCCH format 4 may be determined according to the length andmaximum code rate of the UCI transmitted by the UE. When the UE usesPUCCH format 2, the UE may transmit HARQ-ACK information and CSIinformation together through the PUCCH. When the number of RBs that theUE may transmit is greater than the maximum number of RBs that PUCCHformat 2, or PUCCH format 3, or PUCCH format 4 may use, the UE maytransmit only the remaining UCI information without transmitting someUCI information according to the priority of the UCI information.

PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configuredthrough the RRC signal to indicate frequency hopping in a slot. Whenfrequency hopping is configured, the index of the RB to be frequencyhopped may be configured with an RRC signal. When PUCCH format 1, PUCCHformat 3, or PUCCH format 4 is transmitted through N OFDM symbols on thetime axis, the first hop may have floor (N/2) OFDM symbols and thesecond hop may have ceiling(N/2) OFDM symbols.

PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configured tobe repeatedly transmitted in a plurality of slots. In this case, thenumber K of slots in which the PUCCH is repeatedly transmitted may beconfigured by the RRC signal. The repeatedly transmitted PUCCHs muststart at an OFDM symbol of the constant position in each slot, and havethe constant length. When one OFDM symbol among OFDM symbols of a slotin which a UE should transmit a PUCCH is indicated as a DL symbol by anRRC signal, the UE may not transmit the PUCCH in a corresponding slotand delay the transmission of the PUCCH to the next slot to transmit thePUCCH.

Meanwhile, in the 3GPP NR system, the UE may performtransmission/reception using a bandwidth less than or equal to thebandwidth of the carrier (or cell). To this end, the UE may beconfigured with a bandwidth part (BWP) consisting of a continuousbandwidth of a portion of the bandwidth of the carrier. A UE operatingaccording to TDD or operating in an unpaired spectrum may receive up tofour DL/UL BWP pairs for one carrier (or cell). In addition, the UE mayactivate one DL/UL BWP pair. A UE operating according to FDD oroperating in a paired spectrum may receive up to 4 DL BWPs on a downlinkcarrier (or cell) and up to 4 UL BWPs on an uplink carrier (or cell).The UE may activate one DL BWP and UL BWP for each carrier (or cell).The UE may not receive or transmit in time-frequency resources otherthan the activated BWP. The activated BWP may be referred to as anactive BWP.

The base station may indicate an activated BWP among the BWPs configuredby the UE through downlink control information (DCI). The BWP indicatedthrough DCI is activated, and other configured BWP(s) are deactivated.In a carrier (or cell) operating in TDD, the base station may include abandwidth part indicator (BPI) indicating the BWP activated in the DCIscheduling the PDSCH or PUSCH to change the DL/UL BWP pair of the UE.The UE may receive a DCI scheduling a PDSCH or a PUSCH and may identifya DL/UL BWP pair activated based on the BPI. In the case of a downlinkcarrier (or cell) operating in FDD, the base station may include a BPIindicating the activated BWP to the DCI scheduling the PDSCH to changethe DL BWP of the UE. In the case of an uplink carrier (or cell)operating in FDD, the base station may include a BPI indicating theactivated BWP to the DCI scheduling the PUSCH to change the UL BWP ofthe UE.

FIG. 8 is a conceptual diagram illustrating carrier aggregation.

The carrier aggregation is a method in which the UE uses a plurality offrequency blocks or cells (in the logical sense) configured with ULresources (or component carriers) and/or DL resources (or componentcarriers) as one large logical frequency band in order for a wirelesscommunication system to use a wider frequency band. One componentcarrier may also be referred to as a term called a Primary cell (PCell)or a Secondary cell (SCell), or a Primary SCell (PScell). However,hereinafter, for convenience of description, the term “componentcarrier” is used.

Referring to FIG. 8 , as an example of a 3GPP NR system, the entiresystem band may include up to 16 component carriers, and each componentcarrier may have a bandwidth of up to 400 MHz. The component carrier mayinclude one or more physically consecutive subcarriers. Although it isshown in FIG. 8 that each of the component carriers has the samebandwidth, this is merely an example, and each component carrier mayhave a different bandwidth. Also, although each component carrier isshown as being adjacent to each other in the frequency axis, thedrawings are shown in a logical concept, and each component carrier maybe physically adjacent to one another, or may be spaced apart.

Different center frequencies may be used for each component carrier.Also, one common center frequency may be used in physically adjacentcomponent carriers. Assuming that all the component carriers arephysically adjacent in the embodiment of FIG. 8 , center frequency A maybe used in all the component carriers. Further, assuming that therespective component carriers are not physically adjacent to each other,center frequency A and the center frequency B can be used in each of thecomponent carriers.

When the total system band is extended by carrier aggregation, thefrequency hand used for communication with each UE can be defined inunits of a component carrier. UE A may use 100 MHz, which is the totalsystem band, and performs communication using all five componentcarriers. UEs B1˜B5 can use only a 20 MHz bandwidth and performcommunication using one component carrier. UEs C1 and C2 may use a 40MHz bandwidth and perform communication using two component carriers,respectively. The two component carriers may be logically/physicallyadjacent or non-adjacent. UE C1 represents the case of using twonon-adjacent component carriers, and UE C2 represents the case of usingtwo adjacent component carriers.

FIG. 9 is a drawing for explaining signal carrier communication andmultiple carrier communication. Particularly, FIG. 9A shows a singlecarrier subframe structure and FIG. 9B shows a multi-carrier subframestructure.

Referring to FIG. 9A, in an FDD mode, a general wireless communicationsystem may perform data transmission or reception through one DL bandand one UL band corresponding thereto. In another specific embodiment,in a TDD mode, the wireless communication system may divide a radioframe into a UL time unit and a DL time unit in a time domain, andperform data transmission or reception through a UL/DL time unit.Referring to FIG. 9B, three 20 MHz component carriers (CCs) can beaggregated into each of UL and DL, so that a bandwidth of 60 MHz can besupported. Each CC may be adjacent or non-adjacent to one another in thefrequency domain. FIG. 9B shows a case where the bandwidth of the UL CCand the bandwidth of the DL CC are the same and symmetric, but thebandwidth of each CC can be determined independently. In addition,asymmetric carrier aggregation with different number of UL CCs and DLCCs is possible. A DL/UL CC allocated/configured to a specific UEthrough RRC may be called as a serving DL/UL CC of the specific UE.

The base station may perform communication with the UE by activatingsome or all of the serving CCs of the UE or deactivating some CCs. Thebase station can change the CC to be activated/deactivated, and changethe number of CCs to be activated/deactivated. If the base stationallocates a CC available for the UE as to be cell-specific orUE-specific, at least one of the allocated CCs can be deactivated,unless the CC allocation for the UE is completely reconfigured or the UEis handed over. One CC that is not deactivated by the UE is called as aPrimary CC (PCC) or a primary cell (PCell), and a CC that the basestation can freely activate/deactivate is called as a Secondary CC (SCC)or a secondary cell (SCell).

Meanwhile, 3GPP NR uses the concept of a cell to manage radio resources.A cell is defined as a combination of DL resources and UL resources,that is, a combination of DL CC and UL CC. A cell may be configured withDL resources alone, or a combination of DL resources and UL resources.When the carrier aggregation is supported, the linkage between thecarrier frequency of the DL resource (or DL CC) and the carrierfrequency of the UL resource (or UL CC) may be indicated by systeminformation. The carrier frequency refers to the center frequency ofeach cell or CC. A cell corresponding to the PCC is referred to as aPCell, and a cell corresponding to the SCC is referred to as an SCell.The carrier corresponding to the PCell in the DL is the DL PCC, and thecarrier corresponding to the PCell in the UL is the UL PCC. Similarly,the carrier corresponding to the SCell in the DL is the DL SCC and thecarrier corresponding to the SCell in the UL is the UL SCC. According toUE capability, the serving cell(s) may be configured with one PCell andzero or more SCells. In the case of UEs that are in the RRC_CONNECTEDstate but not configured for carrier aggregation or that do not supportcarrier aggregation, there is only one serving cell configured only withPCell.

As mentioned above, the term “cell” used in carrier aggregation isdistinguished from the term “cell” which refers to a certaingeographical area in which a communication service is provided by onebase station or one antenna group. That is, one component carrier mayalso be referred to as a scheduling cell, a scheduled cell, a primarycell (PCell), a secondary cell (SCell), or a primary SCell (PScell).However, in order to distinguish between a cell referring to a certaingeographical area and a cell of carrier aggregation, in the presentdisclosure, a cell of a carrier aggregation is referred to as a CC, anda cell of a geographical area is referred to as a cell.

FIG. 10 is a diagram showing an example in which a cross carrierscheduling technique is applied. When cross carrier scheduling is set,the control channel transmitted through the first CC may schedule a datachannel transmitted through the first CC or the second CC using acarrier indicator field (CIF). The CIF is included in the DCI. In otherwords, a scheduling cell is set, and the DL grant/UL grant transmittedin the PDCCH area of the scheduling cell schedules the PDSCH/PUSCH ofthe scheduled cell. That is, a search area for the plurality ofcomponent carriers exists in the PDCCH area of the scheduling cell. APCell may be basically a scheduling cell, and a specific SCell may bedesignated as a scheduling cell by an upper layer.

In the embodiment of FIG. 10 , it is assumed that three DL CCs aremerged. Here, it is assumed that DL component carrier #0 is DL PCC (orPCell), and DL component carrier #1 and DL component carrier #2 are DLSCCs (or SCell). In addition, it is assumed that the DL PCC is set tothe PDCCH monitoring CC. When cross-carrier scheduling is not configuredby UE-specific (or UE-group-specific or cell-specific) higher layersignaling, a CIF is disabled, and each DL CC can transmit only a PDCCHfor scheduling its PDSCH without the CIF according to an NR PDCCH rule(non-cross-carrier scheduling, self-carrier scheduling). Meanwhile, ifcross-carrier scheduling is configured by UE-specific (orUE-group-specific or cell-specific) higher layer signaling, a CIF isenabled, and a specific CC (e.g., DL PCC) may transmit not only thePDCCH for scheduling the PDSCH of the DL CC A using the CIF but also thePDCCH for scheduling the PDSCH of another CC (cross-carrier scheduling).On the other hand, a PDCCH is not transmitted in another DL CC.Accordingly, the UE monitors the PDCCH not including the CIF to receivea self-carrier scheduled PDSCH depending on whether the cross-carrierscheduling is configured for the UE, or monitors the PDCCH including theCIF to receive the cross-carrier scheduled PDSCH.

On the other hand, FIGS. 9 and 10 illustrate the subframe structure ofthe 3GPP LTE-A system, and the same or similar configuration may beapplied to the 3GPP NR system. However, in the 3GPP NR system, thesubframes of FIGS. 9 and 10 may be replaced with slots.

FIG. 11 is a block diagram showing the configurations of a UE and a basestation according to an embodiment of the present disclosure. In anembodiment of the present disclosure, the UE may be implemented withvarious types of wireless communication devices or computing devicesthat are guaranteed to be portable and mobile. The UE may be referred toas a User Equipment (UE), a Station (STA), a Mobile Subscriber (MS), orthe like. In addition, in an embodiment of the present disclosure, thebase station controls and manages a cell (e.g., a macro cell, a femtocell, a pico cell, etc.) corresponding to a service area, and performsfunctions of a signal transmission, a channel designation, a channelmonitoring, a self diagnosis, a relay, or the like. The base station maybe referred to as next Generation NodeB (gNB) or Access Point (AP).

As shown in the drawing, a UE 100 according to an embodiment of thepresent disclosure may include a processor 110, a communication module120, a memory 130, a user interface 140, and a display unit 150.

First, the processor 110 may execute various instructions or programsand process data within the UE 100. In addition, the processor 110 maycontrol the entire operation including each unit of the UE 100, and maycontrol the transmission/reception of data between the units. Here, theprocessor 110 may be configured to perform an operation according to theembodiments described in the present disclosure. For example, theprocessor 110 may receive slot configuration information, determine aslot configuration based on the slot configuration information, andperform communication according to the determined slot configuration.

Next, the communication module 120 may be an integrated module thatperforms wireless communication using a wireless communication networkand a wireless LAN access using a wireless LAN. For this, thecommunication module 120 may include a plurality of network interfacecards (NICs) such as cellular communication interface cards 121 and 122and an unlicensed band communication interface card 123 in an internalor external form. In the drawing, the communication module 120 is shownas an integral integration module, but unlike the drawing, each networkinterface card can be independently arranged according to a circuitconfiguration or usage.

The cellular communication interface card 121 may transmit or receive aradio signal with at least one of the base station 200, an externaldevice, and a server by using a mobile communication network and providea cellular communication service in a first frequency band based on theinstructions from the processor 110. According to an embodiment, thecellular communication interface card 121 may include at least one NICmodule using a frequency band of less than 6 GHz. At least one NICmodule of the cellular communication interface card 121 mayindependently perform cellular communication with at least one of thebase station 200, an external device, and a server in accordance withcellular communication standards or protocols in the frequency bandsbelow 6 GHz supported by the corresponding NIC module.

The cellular communication interface card 122 may transmit or receive aradio signal with at least one of the base station 200, an externaldevice, and a server by using a mobile communication network and providea cellular communication service in a second frequency band based on theinstructions from the processor 110. According to an embodiment, thecellular communication interface card 122 may include at least one NICmodule using a frequency band of more than 6 GHz. At least one NTCmodule of the cellular communication interface card 122 mayindependently perform cellular communication with at least one of thebase station 200, an external device, and a server in accordance withcellular communication standards or protocols in the frequency bands of6 GHz or more supported by the corresponding NIC module.

The unlicensed band communication interface card 123 transmits orreceives a radio signal with at least one of the base station 200, anexternal device, and a server by using a third frequency band which isan unlicensed band, and provides an unlicensed band communicationservice based on the instructions from the processor 110. The unlicensedband communication interface card 123 may include at least one NICmodule using an unlicensed band. For example, the unlicensed band may bea band of 2.4 GHz or 5 GHz. At least one NIC module of the unlicensedband communication interface card 123 may independently or dependentlyperform wireless communication with at least one of the base station200, an external device, and a server according to the unlicensed bandcommunication standard or protocol of the frequency band supported bythe corresponding NIC module.

The memory 130 stores a control program used in the UE 100 and variouskinds of data therefor. Such a control program may include a prescribedprogram required for performing wireless communication with at least oneamong the base station 200, an external device, and a server.

Next, the user interface 140 includes various kinds of input/outputmeans provided in the UE 100. In other words, the user interface 140 mayreceive a user input using various input means, and the processor 110may control the UE 100 based on the received user input. In addition,the user interface 140 may perform an output based on instructions fromthe processor 110 using various kinds of output means.

Next, the display unit 150 outputs various images on a display screen.The display unit 150 may output various display objects such as contentexecuted by the processor 110 or a user interface based on controlinstructions from the processor 110.

In addition, the base station 200 according to an embodiment of thepresent disclosure may include a processor 210, a communication module220, and a memory 230.

First, the processor 210 may execute various instructions or programs,and process internal data of the base station 200. In addition, theprocessor 210 may control the entire operations of units in the basestation 200, and control data transmission and reception between theunits. Here, the processor 210 may be configured to perform operationsaccording to embodiments described in the present disclosure. Forexample, the processor 210 may signal slot configuration and performcommunication according to the signaled slot configuration.

Next, the communication module 220 may be an integrated module thatperforms wireless communication using a wireless communication networkand a wireless LAN access using a wireless LAN. For this, thecommunication module 120 may include a plurality of network interfacecards such as cellular communication interface cards 221 and 222 and anunlicensed band communication interface card 223 in an internal orexternal form. In the drawing, the communication module 220 is shown asan integral integration module, but unlike the drawing, each networkinterface card can be independently arranged according to a circuitconfiguration or usage.

The cellular communication interface card 221 may transmit or receive aradio signal with at least one of the UE 100, an external device, and aserver by using a mobile communication network and provide a cellularcommunication service in the first frequency hand based on theinstructions from the processor 210. According to an embodiment, thecellular communication interface card 221 may include at least one NICmodule using a frequency band of less than 6 GHz. The at least one NICmodule of the cellular communication interface card 221 mayindependently perform cellular communication with at least one of the UE100, an external device, and a server in accordance with the cellularcommunication standards or protocols in the frequency bands less than 6GHz supported by the corresponding NIC module.

The cellular communication interface card 222 may transmit or receive aradio signal with at least one of the UE 100, an external device, and aserver by using a mobile communication network and provide a cellularcommunication service in the second frequency band based on theinstructions from the processor 210. According to an embodiment, thecellular communication interface card 222 may include at least one NICmodule using a frequency band of 6 GHz or more. The at least one NICmodule of the cellular communication interface card 222 mayindependently perform cellular communication with at least one of thebase station 100, an external device, and a server in accordance withthe cellular communication standards or protocols in the frequency bands6 GHz or more supported by the corresponding NIC module.

The unlicensed band communication interface card 223 transmits orreceives a radio signal with at least one of the base station 100, anexternal device, and a server by using the third frequency band which isan unlicensed band, and provides an unlicensed band communicationservice based on the instructions from the processor 210. The unlicensedband communication interface card 223 may include at least one NICmodule using an unlicensed band. For example, the unlicensed band may bea band of 2.4 GHz or 5 GHz. At least one NIC module of the unlicensedband communication interface card 223 may independently or dependentlyperform wireless communication with at least one of the UE 100, anexternal device, and a server according to the unlicensed bandcommunication standards or protocols of the frequency band supported bythe corresponding NIC module.

FIG. 11 is a block diagram illustrating the UE 100 and the base station200 according to an embodiment of the present disclosure, and blocksseparately shown are logically divided elements of a device.Accordingly, the aforementioned elements of the device may be mounted ina single chip or a plurality of chips according to the design of thedevice. In addition, a part of the configuration of the UE 100, forexample, a user interface 140, a display unit 150 and the like may beselectively provided in the UE 100. In addition, the user interface 140,the display unit 150 and the like may be additionally provided in thebase station 200, if necessary.

In the NR wireless communication system, the UE may signal whether adownlink signal or a downlink channel is successfully received bytransmitting a codebook including hybrid automatic repeat request(HARQ)-ACK information. The HARQ-ACK codebook includes one or more bitsindicating whether reception of a downlink channel or downlink signal issuccessful. Here, the downlink channel may include at least one of aphysical downlink shared channel (PDSCH), a semi-persistence scheduling(SPS) PDCSH, and a PDCCH releasing the PCSH and SPS PDSCH. The HARQ-ACKcodebook may be divided into a semi-static HARQ-ACK codebook and adynamic HARQ-ACK codebook. The base station may set one of the twoHARQ-ACK codebooks to the UE. The UE may use the HARQ-ACK codebook setfor the UE.

When the semi-static HARQ-ACK codebook is used, the base station may usethe RRC signal to set the number of bits of the HARQ-ACK codebook andinformation for determining which channel or signal is successfullyreceived by each bit of the HARQ-ACK codebook. Therefore, the basestation does not need to signal information necessary for HARQ-ACKcodebook transmission to the UE whenever HARQ-ACK codebook transmissionis required.

When a dynamic HARQ-ACK codebook is used, the base station may signalinformation necessary for generating the HARQ-ACK codebook through thePDCCH. Specifically, the base station may signal information necessaryfor HARQ-ACK codebook generation through a downlink assignment index(DAI) of the DCI of the PDCCH. In a specific embodiment, the DAIindicates information on the number of bits of the HARQ-ACK codebookincluded in the HARQ-ACK codebook and information on which channel orsignal reception is successful in each bit of the HARQ-ACK codebook. TheUE may receive the DAI through the PDCCH scheduling the PDSCH. DAI maybe divided into counter-DAI and total-DAI. Total-DAI represents thenumber of channels or signals for which reception success is indicatedthrough the same HARQ-ACK codebook. The counter-DAI indicates theHARQ-ACK codebook bit indicating whether the reception is successful orthe channel indicating whether the reception is successful or not isindicated through the same HARQ-ACK codebook. The DCI scheduling thePDSCH may include a counter-DAI value corresponding to the scheduledPDSCH. In addition, the DCI scheduling the PDSCH may include a total-DAIvalue corresponding to the scheduled PDSCH. The UE may determine thenumber of bits of the dynamic HARQ-ACK codebook, based on informationsignaled by the PDCCH. Specifically, the UE may determine the number ofbits of the dynamic HARQ-ACK codebook, based on the DAI of the DCI ofthe PDCCH.

FIGS. 12A and 12B illustrate that a UE generates a dynamic HARQ-ACKcodebook and transmits it to a base station according to an embodimentof the present disclosure.

When the UE receives one or more PDCCHs for scheduling a channel and asignal indicating success or failure of reception with a specificHARQ-ACK codebook, the UE may transmit a dynamic HARQ-ACK codebook,based on the last received PDCCH. Specifically, the UE may transmit thePUCCH including the HARQ-ACK codebook in the resource indicated by thePDCCH last received by the UE. The PDCCH last received by the UErepresents a PDCCH last received by the UE among PDCCHs for scheduling asignal or channel indicating whether reception is successful or notthrough the HARQ-ACK codebook. In the present disclosure, unlessotherwise specified, a resource represents a combination of a timeresource and a frequency resource. Here, the time resource includes anOFDM symbol, and the frequency resource includes a physical resourceblock (PRB). In addition, for convenience of description, when the UEreceives one or more PDCCHs for scheduling a channel and a signalindicating whether reception is successful in the same HARQ-ACKcodebook, the last PDCCH received by the UE is referred to as the lastPDCCH. In FIGS. 12(a) and 12(b), the UE receives two PDCCHs, and each ofthe two PDCCHs schedules a PDSCH. Since the PDCCHs are received indifferent CORESETs, search spaces, or OFDM symbols in FIG. 12(a), the UEcan clearly determine which PDCCH is the last PDCCH, and can transmit aPUCCH including a HARQ-ACK codebook in a resource indicated by thecorresponding PDCCH. For example, the UE may determine a PDCCH in whichthe start symbol is later among the two PDCCHs as the last PDCCH.Alternatively, the UE may determine a PDCCH in which the last symbol islater among the two PDCCHs as the last PDCCH. In FIG. 12(b), the UEreceives a plurality of PDCCHs in one search space or the same OFDMsymbol. Therefore, the UE cannot clearly determine which PDCCH is thelast PDCCH and cannot determine a resource to transmit a PUCCH includinga HARQ-ACK codebook. Therefore, there is a need for a method for the UEto determine the last PDCCH even in this case.

The UE may determine the last PDCCH, based on the symbol on which thePDCCH is received. Specifically, the UE may determine the PDCCH havingthe latest start symbol of the PDCCH among the plurality of PDCCHs asthe last PDCCH. In addition, the UE may determine the PDCCH in which thelast symbol of the PDCCH ends last among the plurality of PDCCHs as thelast PDCCH. When the UE determines the last PDCCH, based on the symbolon which the PDCCH is received, the UE may not be able to determine thelast PDCCH only with the symbol on which the PDCCH is received. Forexample, one or more symbols for receiving a plurality of PDCCHs may bethe same. In the present disclosure, the fact that one or more symbolsfor receiving a plurality of PDCCHs are the same may include that thestart symbols of the plurality of PDCCHs are the same. In addition, thefact that the plurality of PDCCHs are received in the same symbol mayinclude that the last symbol of each of the plurality of PDCCHs is thesame. In addition, the fact that one or more symbols for receiving aplurality of PDCCHs are the same may indicate that the start symbols ofthe plurality of PDCCHs are the same and that the end symbols of theplurality of PDCCHs are the same. When it is not possible to determinethe last PDCCH, based on the symbol on which the PDCCH is received, theUE may determine the last PDCCH, based on the cell index of the cell inwhich the PDCCH is received and the symbol on which the PDCCH isreceived. When one or more symbols in which a plurality of PDCCHs arereceived arc the same, the UE may determine a PDCCH having a high cellindex of a cell in which the PDCCH is received as a late-order PDCCH.There may be a problem in which a plurality of PDCCHs are received inone cell and in which one or more symbols in which a plurality of PDCCHsare received are the same.

The UE may determine the last PDCCH, based on the symbol at which thePDCCH is received, the cell index of the cell where the PDCCH isreceived, and the index of a physical resource block (PRB) to which thePDCCH is mapped. The UE may not be able to determine the last PDCCH,based on the symbol for receiving the PDCCH and the cell index of thecell in which the PDCCH is received. Specifically, the PDCCH may bereceived in the same symbol of the same cell. In this case, the UE maydetermine the last PDCCH, based on the lowest value among the indexes ofthe PRBs to which each of the plurality of PDCCHs is mapped. In aspecific embodiment, when a plurality of PDCCHs receive a PDCCH in thesame symbol of the same cell, the UE may determine the PDCCH having thelargest lowest value among the indexes of the PRBs to which each of theplurality of PDCCHs is mapped as the last PDCCH of the plurality ofPDCCHs. For example, if the lowest value among the indexes of the PRBsto which the first PDCCH is mapped is 10 and the lowest value among theindexes of the PRB s to which the second PDCCH is mapped is 8, the UEmay determine that the first PDCCH is a later order of the PDCCH thanthe second PDCCH. The PRB index may be a cell common PRB index. Inaddition, the index of the PRB may be a PRB index in the BWP.

In addition, the UE may determine the last PDCCH, based on the symbol atwhich the PDCCH is received, the cell index of the cell where the PDCCHis received, and the index of the CORESET to which the PDCCH is mapped.The UE may not be able to determine the last PDCCH, based on the symbolfor receiving the PDCCH and the cell index of the cell in which thePDCCH is received. Specifically, a plurality of PDCCHs may be receivedin one symbol of one cell. In this case, the UE may determine the lastPDCCH, based on the index of the CORESET to which the plurality ofPDCCHs are mapped. In a specific embodiment, when a plurality of PDCCHsare received in one symbol of one cell, the UE may determine the PDCCHhaving the largest index of the CORESET to which the PDCCH is mappedamong the plurality of PDCCHs as the last PDCCH among the plurality ofPDCCHs.

FIG. 13 illustrates a case where one PDCCH is received from a resourcemapped by a plurality of CORESETs.

As illustrated in FIG. 13 , one PDCCH may be received in a resourcemapped to a plurality of CORESETs. In this case, the UE may determinethat the corresponding PDCCH is mapped or received from a CORSET havinga high index among a plurality of CORESETs. In another specificembodiment, when one PDCCH is received from a resource mapped to aplurality of CORESETs, the UE may determine that the corresponding PDCCHis mapped or received from a CORSET having a high index among theplurality of CORESETs.

In addition, the UE may determine the last PDCCH, based on the symbol atwhich the PDCCH is received, the cell index of the cell where the PDCCHis received, the index of the CORESET to which the PDCCH is mapped, andthe order of the lowest CCE to which the PDCCH is mapped. The UE may notbe able to determine the last PDCCH, based on the symbol for receivingthe PDCCH, the cell index of the cell where the PDCCH is received, andthe index of the CORESET to which the PDCCH is mapped. Specifically, aplurality of PDCCHs may be received in the same symbol of the same cell,and a plurality of PDCCHs may be mapped to the same CORSET. In thiscase, the UE may determine the last PDCCH, based on the order of thelowest CCE to which the PDCCH is mapped. In a specific embodiment, whena plurality of PDCCHs are received in the same symbol of the same celland a plurality of PDCCHs are mapped to the same CORSET, the UE maydetermine the PDCCH having the largest index of the lowest CCE to whichthe PDCCH is mapped as the last PDCCH among the plurality of PDCCHs.

In another specific embodiment, the UE may expect that resources forPUCCH transmission indicated by a plurality of PDCCHs received at thesame time point are the same. That is, the UE may operate on the premisethat the resources for PUCCH transmission indicated by a plurality ofPDCCHs received at the same time point are the same. The UE may considerthat resources for PUCCH transmission indicated by a plurality of PDCCHsreceived at the same time point are the same. In this embodiment, when aPDCCH is received at a plurality of time points, the UE does not need todetermine which of the plurality of PDCCHs is the last PDCCH. Inaddition, when a plurality of PDCCHs received at the same time point todifferent PUCCH resources, the UE may determine that the plurality ofPDCCHs are not valid. In addition, when the base station transmits aplurality of PDCCHs at the same time, the base station cannot set theDCI field of the PDCCH so that the plurality of PDCCHs indicatedifferent PUCCH resources. The plurality of PDCCHs received at the sametime may include one or more of the same symbols for receiving theplurality of PDCCHs. As described above, the fact that one or moresymbols for receiving a plurality of PDCCHs are the same may includethat the start symbols of the plurality of PDCCHs are the same. Inaddition, when one or more symbols for receiving a plurality of PDCCHsare the same, it may indicate that the start symbols of the plurality ofPDCCHs arc the same and that the end symbols of the plurality of PDCCHsare the same. In addition, when one or more symbols for receiving aplurality of PDCCHs are the same, it may indicate that the start symbolsof the plurality of PDCCHs are the same and that the end symbols of theplurality of PDCCHs are the same.

In addition, a method of arranging HARQ-ACK information bits accordingto the order of the counter-DAI field in the dynamic HARQ-ACK codebookwill be described. When the UE aligns the HARQ-ACK information bitsaccording to the counter-DAI field in the dynamic HARQ-ACK codebook, theUE may apply embodiments similar to the method of determining the lastPDCCH for determining the PUCCH resource in which the dynamic HARQ-ACKcodebook is transmitted. The UE may determine the sorting order of theHARQ-ACK information bits corresponding to the counter-DAI field of eachPDCCH in the dynamic HARQ-ACK codebook according to the cell index ofthe PDCCH and the index of the symbol in which the PDCCH is received. InFIG. 12(a), in the dynamic HARQ-ACK codebook, the HARQ-ACK informationbit corresponding to the counter-DAI (C-DAI) value of the PDCCHpreceding in time may be arranged at a position preceding the HARQ-ACKinformation bit corresponding to the counter-DAI (C-DAI) value of thePDCCH following in time. Specifically, when the symbols for receiving aplurality of PDCCHs are the same, the UE may first arrange the HARQ-ACKinformation bit corresponding to the counter-DAI field of the PDCCHcorresponding to the index of the relatively low cell in the dynamicHARQ-ACK codebook, and then arrange the HARQ-ACK information bitcorresponding to a counter-DAI field corresponding to a relatively highcell index. When the symbols for receiving a plurality of PDCCHs are thesame and all of the plurality of PDCCHs correspond to a specific cell,there is a need for a method of aligning hits indicating HARQ-ACKcorresponding to a counter-DAI field of each of a plurality of PDCCHs ina dynamic HARQ-ACK codebook. In FIG. 12(b), since the two PDCCHs in thedynamic HARQ-ACK codebook are received by the same symbol, it should bedetermined whether the HARQ-ACK information bit corresponding to thevalue of one counter-DAI (C-DAI) should be arranged prior to theHARQ-ACK information bit corresponding to the value of anothercounter-DAI (C-DAI).

When the UE is unable to sort the HARQ-ACK information bits according tothe counter-DAI field, based on the symbol at which each of theplurality of PDCCHs is received and the cell index corresponding to eachof the plurality of PDCCHs, the UE may arrange the HARQ-ACK informationbits corresponding to the counter-DAI field of each of the plurality ofPDCCHs in the dynamic HARQ-ACK codebook, based on the PRB to which eachof the plurality of PDCCHs is mapped. In a specific embodiment, when theUE is unable to sort the HARQ-ACK information bits corresponding to theplurality of counter-DAI fields, based on the symbol at which each ofthe plurality of PDCCHs is received and the cell index corresponding toeach of the plurality of PDCCHs, the UE may sort the HARQ-ACKinformation hits corresponding to the counter-DAI field of each of theplurality of PDCCHs in the dynamic HARQ-ACK codebook, based on the PRBhaving the lowest index among the PRBs to which each of the plurality ofPDCCHs is mapped. For example, when the UE is unable to sort theHARQ-ACK information bits corresponding to the counter-DAI field of eachof the plurality of PDCCHs, based on the symbol at which the PDCCH isreceived and the cell index corresponding to the PDCCH, the UE mayarrange the HARQ-ACK information bits in the order from the HARQ-ACKinformation bit corresponding to the counter-DAI field of the PDCCH withthe lowest index relatively low among the PRBs to which the PDCCH ismapped to the HARQ-ACK information bit corresponding to the counter-DAIfield of the PDCCH with the lowest index relatively high among the PRBsto which the PDCCH is mapped in the dynamic HARQ-ACK codebook. When thelowest index among PRBs mapped to the first PDCCH is 10 and the lowestindex among PRBs mapped to the second PDCCH is 8, the UE arranges theHARQ-ACK information bit corresponding to the counter-DAI field of thesecond PDCCH prior to the HARQ-ACK information bit corresponding to thecounter-DAI field of the first PDCCH. A case the UE is unable to alignthe HARQ-ACK information bits corresponding to the counter-DAI field ofeach of the plurality of PDCCHs, based on the symbol at which each ofthe plurality of PDCCHs is received and the cell index corresponding toeach of the plurality of PDCCHs may include a case in which a pluralityof PDCCHs are received in one symbol and all of the plurality of PDCCHscorrespond to a specific cell index.

When the UE is unable to sort the HARQ-ACK information bitscorresponding to the counter-DAI field of each of the plurality ofPDCCHs, based on the symbol at which each of the plurality of PDCCHs isreceived and the cell index corresponding to each of the plurality ofPDCCHs, the UE may sort the HARQ-ACK information bits corresponding tothe counter-DAI field of each of the plurality of PDCCHs in the dynamicHARQ-ACK codebook, based on the index of the CORESET to which each ofthe plurality of PDCCHs is mapped. In a specific embodiment, when the UEis unable to sort the HARQ-ACK information bits corresponding to thecounter-DAI field of each of the plurality of PDCCHs, based on thesymbol at which each of the plurality of PDCCHs is received and the cellindex corresponding to each of the plurality of PDCCHs, the UE may sortthe HARQ-ACK information bits corresponding to the counter-DAI field ofeach of the plurality of PDCCHs in the dynamic HARQ-ACK codebook, basedon the index of the CORESET to which each of the plurality of PDCCHs ismapped. For example, when the UE is unable to sort the HARQ-ACKinformation bits corresponding to the counter-DAI field of each of theplurality of PDCCHs, based on the symbol for receiving the PDCCH and thecell index corresponding to the PDCCH, in the dynamic HARQ-ACK codebook,the UE may arrange the HARQ-ACK information bits in the order of theHARQ-ACK information bit corresponding to the counter-DAI field of thePDCCH with a relatively low index of the CORESET to which the PDCCH ismapped to the HARQ-ACK information bit corresponding to the counter-DAIfield of the PDCCH with a relatively high index of the CORESET to whichthe PDCCH is mapped. As described above, when the UE is unable to sortthe HARQ-ACK information bits corresponding to the counter-DAI field ofeach of the plurality of PDCCHs, based on the symbol at which each ofthe plurality of PDCCHs is received and the cell index corresponding toeach of the plurality of PDCCHs, a case in which a plurality of PDCCHsare received in one symbol and all of the plurality of PDCCHs correspondto a specific cell index may be included. The UE may not be able to sortthe HARQ-ACK information bits corresponding to the counter-DAI field ofeach PDCCH, based on a symbol at which each of the plurality of PDCCHsis received, a cell index corresponding to each of the plurality ofPDCCHs, and an index of a CORESET mapped to each of the plurality ofPDCCHs. In this case, the UE may sort the HARQ-ACK information bitscorresponding to the counter-DAI field of each of the plurality ofPDCCHs in the dynamic HARQ-ACK codebook, based on the order of thecontrol channel element (CCE) to which each of the plurality of PDCCHsis mapped. One PDCCH may be received in resources mapped to a pluralityof CORESETs. In this case, the UE may determine that the correspondingPDCCH is mapped or received from a CORSET having a high index among aplurality of CORESETs. In another specific embodiment, when one PDCCH isreceived from a resource mapped to a plurality of CORESETs, the UE maydetermine that the corresponding PDCCH is mapped or received from aCORSET having a high index among the plurality of CORESETs.

When the UE is unable to sort the HARQ-ACK information bitscorresponding to the counter-DAI field of each of the plurality ofPDCCHs, based on the symbol at which each of the plurality of PDCCHs isreceived and the cell index corresponding to each of the plurality ofPDCCHs, the UE may sort the HARQ-ACK information bits corresponding tothe counter-DAI field of each of the plurality of PDCCHs in the dynamicHARQ-ACK codebook, based on the value of the counter-DAI field of eachof the plurality of PDCCHs. In a specific embodiment, when the UE isunable to sort the HARQ-ACK information bits corresponding to thecounter-DAI field, based on the symbol at which each of the plurality ofPDCCHs is received and the cell index corresponding to each of theplurality of PDCCHs, the UE may sort the HARQ-ACK information bitscorresponding to the counter-DAI field of each of the plurality ofPDCCHs in the dynamic HARQ-ACK codebook, based on the value of thecounter-DAI field of each of the plurality of PDCCHs. For example, whenthe UE is unable to sort the HARQ-ACK information bits corresponding tothe counter-DAI field, based on the symbol at which the PDCCH isreceived and the cell index corresponding to the PDCCH, in the dynamicHARQ-ACK codebook, the UE may sort the HARQ-ACK information bits inorder from the HARQ-ACK information bit in the counter-DAI field of thePDCCH including the counter-DAI field having a relatively low value tothe HARQ-ACK information bit corresponding to a counter-DAI field of aPDCCH including a counter-DAI field having a relatively high value. Whenthe value of the counter-DAI field of the first PDCCH is 1 and the valueof the counter-DAI field of the second PDCCH is 2, in the dynamicHARQ-ACK codebook, the UE may place the HARQ-ACK information bitcorresponding to the counter-DAI of the first PDCCH in front and mayplace the HARQ-ACK information bit corresponding to the counter-DAI ofthe second PDCCH relatively to the rear.

The types of scheduling for downlink transmission may be classified intodynamic scheduling and semi-persistent scheduling (SPS). Dynamicscheduling refers to scheduling by DCI. SPS represents scheduling by RRCsignaling. When the SPS PDSCH is configured to the UE, the base stationmay release the SPS PDSCH reception configuration by transmitting theSPS PDSCH release PDCCH to the UE. At this time, the SPS PDSCH releasePDCCH represents a PDCCH indicating SPS PDSCH release. Hereinafter, amethod of transmitting the HARQ-ACK for the SPS PDSCH release PDCCH bythe UE will be described.

FIG. 14 illustrates a method for a UE to transmit HARQ-ACK for an SPSPDSCH release PDCCH using a semi-static HARQ-ACK codebook according toan embodiment of the present disclosure.

When the SPS PDSCH is configured, the UE may add a 1-bit HARQ-ACKindicating whether reception of the SPS PDSCH release PDCCH issuccessful to the semi-static HARQ-ACK codebook. In more detail, the UEmay add a 1-bit HARQ-ACK for success in reception of the SPS PDSCHrelease PDCCH to the end of the semi-static HARQ-ACK codebook. When theSPS PDSCH is not configured, the UE does not need to add a 1-bitHARQ-ACK for whether the reception of the SPS PDSCH release PDCCH issuccessful to the semi-static HARQ-ACK codebook. In this embodiment,when the SPS PDSCH is configured, uplink control information to betransmitted by the UE increases. Accordingly, the coverage of the uplinkcontrol channel is reduced. This embodiment may be equally applied evenwhen a plurality of SPS PDSCHs are configured in the UE. In this case,the UE may add a plurality of bits each corresponding to the HARQ-ACKfor the plurality of SPS PDSCH release PDCCHs to the dynamic HARQ-ACKcodebook. In this case, each of the plurality of SPS PDSCH releasePDCCHs corresponds to the plurality of SPS PDSCHs.

In another specific embodiment, when the SPS PDSCH is configured to theUE, the UE may transmit whether the SPS PDSCH release PDCCH issuccessfully received instead of whether the SPS PDSCH is successfullyreceived in the semi-static HARQ-ACK codebook. That is, the UE maytransmit 1 bit of HARQ-ACK indicating whether the reception of the SPSPDSCH release PDCCH is successful instead of 1 bit of HARQ-ACKindicating whether the reception of the SPS PDSCH is successful in thesemi-static HARQ-ACK codebook. In this case, the UE may set the value ofthe corresponding bit in the HARQ-ACK for the SPS PDSCH in thesemi-static HARQ-ACK codebook as the HARQ-ACK for the SPS PDSCH releasePDCCH. In FIG. 14 , a number indicates the position of a bit indicatingwhether reception is successful or not in the semi-static HARQ-ACKcodebook. In the embodiment of FIG. 14 , the UE is configured to receivethe SPS PDSCH in the 9th symbol and the 10th symbol of the slot, and theHARQ-ACK for the configured SPS PDSCH is located in the fifth bit in thesemi-static HARQ-ACK codebook. After the UE receives the SPS PDSCH butbefore transmitting the HARQ-ACK for the SPS PDSCH, the UE receives theSPS release PDCCH. The UE inserts a bit indicating the HARQ-ACK for theSPS PDSCH release PDCCH in the fifth bit of the semi-static HARQ-ACKcodebook, and transmits the semi-static HARQ-ACK codebook to the basestation. According to this embodiment, a time period in which the basestation can transmit the SPS PDSCH release PDCCH may be limited. Thiswill be described with reference to FIG. 15 .

FIG. 15 illustrates a time interval in which a base station can transmitan SPS PDSCH release PDCCH according to an embodiment of the presentdisclosure.

In the above-described embodiment, the HARQ-ACK information bitindicating whether the reception of the SPS PDSCH release PDCCH sent bythe base station is successful should be the same as the semi-staticHARQ-ACK codebook including the HARQ-ACK information bit indicatingsuccess in reception of the SPS PDSCH. At this time, the PUCCH indicatedby the SPS PDSCH release PDCCH should be the same as the PUCCHtransmitting the semi-static HARQ-ACK codebook including the HARQ-ACKinformation bit indicating whether or not the SPS PDSCH is successfullyreceived. In addition, after receiving the PDSCH, the PUCCH timeinterval including the HARQ-ACK for the PDSCH is limited to K1 slots,and K1 may be set by an RRC signal. Accordingly, the timing at which thebase station can transmit the SPS PDSCH release PDCCH may be limited toa period from the time point when the PUCCH is transmitted to the timepoint when the PUCCH before K1 slots is transmitted. FIG. 15(a)illustrates a time interval from the time point when the PUCCH istransmitted to the time point when the PUCCH before K1 slots istransmitted.

In another specific embodiment, when the SPS PDSCH is set to the UE andthe UE receives the SPS PDSCH release PDCCH, in the semi-static HARQ-ACKcodebook including the HARQ-ACK for SPS PDSCH reception set first afterreceiving the SPS PDSCH release PDCCH, the UE may transmit a bitindicating HARQ-ACK for the SPS PDSCH release PDCCH instead of the hitindicating HARQ-ACK for the SPS PDSCH. At this time, the UE may set thevalue of the corresponding bit in the HARQ-ACK for the SPS PDSCH in thesemi-static HARQ-ACK codebook of the PUCCH including the HARQ-ACK forthe SPS PDSCH as HARQ-ACK for the SPS PDSCH release PDCCH. Specifically,when the UE receives the SPS PDSCH release PDCCH in the nth slot and theslot in which the first SPS PDSCH reception set after the nth slot isset is the n+X^(th) slot, the UE may insert a bit indicating HARQ-ACKfor the SPS PDSCH release PDCCH in the semi-static HARQ-ACK codebook forSPS PDSCH reception configured in the n+X^(th) slot. In this embodiment,the base station may transmit the SPS PDSCH release PDCCH to the UEwithout any particular timing limitation. FIG. 15(b) illustrates a timeperiod in which the base station can transmit the SPS PDSCH releasePDCCH. However, it may take a long time from when the base stationtransmits the SPS PDSCH release PDCCH to the time when the UE transmitsthe HARQ-ACK for the SPS PDSCH release PDCCH.

In another specific embodiment, the UE may determine the semi-staticHARQ-ACK codebook and PUCCH resource for transmitting the HARQ-ACK forthe SPS PDSCH release PDCCH, based on the time-domain resourceassignment (TDRA) field of the SPS PDSCH release PDCCH. Here, the TDRAfield is a field indicating information on the time domain allocationinformation of the PDSCH (i.e., the position of the symbol where thePDSCH starts, the length of the PDSCH) and the position of the DM-RS.The base station can set up to 16 TDRAs to the UE. The UE may receive anindication of one TDRA among the 16 TDRA fields of the PDCCH, and maydetermine the position of the symbol where the PDSCH starts, the lengthof the PDSCH, and the position of the DM-RS according to thecorresponding TDRA. The SPS PDSCH release PDCCH includes a TDRA field,but since the PDSCH is not scheduled, the TDRA field is not used.Specifically, the UE may determine which bit of the semi-static HARQ-ACKcodebook should be inserted into the HARQ-ACK for the SPS PDSCH releasePDCCH according to the time domain allocation information of the PDSCHindicated by the TDRA field of the SPS PDSCH release PDCCH. In thiscase, when the PDSCH is scheduled according to the time domainallocation information of the PDSCH indicated by the TDRA field, whetheror not the SPS PDSCH release PDCCH is successfully received may beinserted into a bit indicating whether the PDSCH is successfullyreceived. It is assumed that the UE does not need to receive anotherchannel or signal in a symbol corresponding to the time domainallocation information of the PDSCH indicated by the TDRA field of theSPS PDSCH release PDCCH. In this embodiment, the UE cannot receive thePDSCH in the resource indicated by the TDRA field of the SPS PDSCHrelease PDCCH.

In this embodiment, the UE may expect that the channel or signal towhich the HARQ-ACK should be transmitted through the semi-staticHARQ-ACK codebook at the HARQ-ACK time point indicated by the SPS PDSCHrelease PDCCH in the resource indicated by the TDRA field of the SPSPDSCH release PDCCH is not scheduled. That is, the UE may operate on thepremise that the channel or signal to which the HARQ-ACK should betransmitted through the semi-static HARQ-ACK codebook at the HARQ-ACKtime point in the resource indicated by the TDRA field of the SPS PDSCHrelease PDCCH is not scheduled. At this time, the HARQ-ACK time pointindicated by the SPS PDSCH release PDCCH is the time point indicated bythe PDSCH-to-HARQ_feedback timing indicator field. Specifically, the UEmay not expect to receive a channel or signal to which HARQ-ACK is to betransmitted through the semi-static HARQ-ACK codebook at the HARQ-ACKtime point indicated by the SPS PDSCH release PDCCH in the resourceindicated by the TDRA field of the SPS PDSCH release PDCCH. That is, inthe resource indicated by the TDRA field of the SPS PDSCH release PDCCH,the UE may operate on the premise that the UE does not receive a channelor signal to which HARQ-ACK is to be transmitted through a semi-staticHARQ-ACK codebook at the HARQ-ACK time point indicated by the SPS PDSCHrelease PDCCH. In the resource indicated by the TDRA field of the SPSPDSCH release PDCCH, when the UE receives a channel or signal to whichHARQ-ACK is to be transmitted through a semi-static HARQ-ACK codebook ata time other than the semi-static HARQ-ACK codebook indicated by the SPSPDSCH release PDCCH, the UE can operate normally. Therefore, in theresource indicated by the TDRA field of the SPS PDSCH release PDCCH, thebase station may transmit a channel or signal to which HARQ-ACK is to betransmitted through a semi-static HARQ-ACK codebook at a time other thanthe semi-static HARQ-ACK codebook indicated by the SPS PDSCH releasePDCCH.

In another specific embodiment, the UE may expect that the channel orsignal is not scheduled for the resource indicated by the TDRA field ofthe SPS PDSCH release PDCCH. That is, the UE may operate on the premisethat a channel or signal is not scheduled for a resource indicated bythe TDRA field of the SPS PDSCH release PDCCH. Specifically, the UE maynot expect to receive a channel or signal from a resource indicated bythe TDRA field of the SPS PDSCH release PDCCH. That is, the UE mayoperate on the premise that the UE does not receive a channel or signalfrom a resource indicated by the TDRA field of the SPS PDSCH releasePDCCH. The base station cannot schedule a channel or signal to whichHARQ-ACK is to be transmitted through the semi-static HARQ-ACK codebookat a time other than the semi-static HARQ-ACK codebook indicated by theSPS PDSCH release PDCCH in the resource indicated by the TDRA field ofthe PDCCH.

The UE may be defined as having to transmit the HARQ-ACK of the PDSCH orSPS PDSCH release PDCCH in a slot corresponding to the HARQ-ACK timepoint indicated by the PDCCH. The semi-static HARQ-ACK codebooktransmitted in a slot other than the slot corresponding to the HARQ-ACKtime point indicated by the PDCCH may transmit the HARQ-ACK of the PDSCHor SPS PDSCH release PDCCH as NACK. Assuming that the SPS PDSCH releasePDCCH indicates the n^(th) slot as the HARQ-ACK time point, the PDSCHtransmitted in the resource region overlapping the resource indicated bythe TDRA field of the SPS PDSCH release PDCCH indicates the m^(th) slotas the HARQ-ACK time point. At this time, in the n^(th) slot, the UEshould transmit HARQ-ACK for the SPS PDSCH release PDCCH, and in them^(th) slot, the UE should transmit the HARQ-ACK for the PDSCHtransmitted in the resource region overlapping the resource indicated bythe TDRA field of the SPS PDSCH release PDCCH. Therefore, in a slotother than the slot corresponding to the HARQ-ACK time point indicatedby the PDCCH, the UE cannot apply the principle that the HARQ-ACK of thePDSCH or SPS PDSCH release PDCCH should be transmitted as NACK.Accordingly, first, the UE may be defined as transmitting the HARQ-ACKof the SPS PDSCH release PDCCH in a slot corresponding to the HARQ-ACKtime point indicated by the SPS PDSCH release PDCCH. When there is aseparate HARQ-ACK to be transmitted at the same location as the locationof the HARQ-ACK for the SPS PDSCH release PDCCH of the HARQ-ACK codebooktransmitted in the corresponding slot, a separate HARQ-ACK istransmitted, in other cases, in a slot other than the slot correspondingto the HARQ-ACK time point indicated by the SPS PDSCH release PDCCH, itmay be specified that the UE transmits the HARQ-ACK of the SPS PDSCHrelease PDCCH as NACK. In the above-described example, in the m^(th)slot, the UE transmits a HARQ-ACK for a PDSCH transmitted in a resourceregion overlapping with a resource indicated by the TDRA field of theSPS PDSCH release PDCCH.

The base station may configure the UE to receive a plurality of SPSPDSCHs to support a plurality of service types. When a plurality of SPSPDSCH receptions arc configured, an SPS PDSCH index may be configuredfor each SPS PDSCH reception configuration in order to distinguishbetween different SPS PDSCHs. That is, the UE can distinguish differentSPS PDSCH reception configurations through the SPS PDSCH index. The basestation may activate the reception of the configured SPS PDSCH bytransmitting the SPS PDSCH activation PDCCH. The SPS PDSCH activationPDCCH may be scrambled with CS-RNTI. In addition, the base station mayrelease the SPS PDSCH set to the UE by transmitting the SPS PDSCHrelease PDCCH. The SPS PDSCH release PDCCH may be scrambled withCS-RNTI. The base station may indicate the SPS PDSCH index in the SPSPDSCH activation PDCCH and the SPS PDSCH release PDCCH. The UE maydetermine which SPS PDSCH should be activated or released among theplurality of SPS PDSCHs according to the instruction of the basestation. Specifically, when the UE receives the SPS PDSCH activationPDCCH, the UE may obtain the index of the SPS PDSCH from the SPS PDSCHactivation PDCCH, and the UE may activate the reception of the SPS PDSCHcorresponding to the index indicated by the SPS PDSCH activation PDCCH.When the UE receives the SPS PDSCH release PDCCH, the UE may obtain theindex of the SPS PDSCH from the SPS PDSCH release PDCCH, and the UE mayrelease the SPS PDSCH reception configuration corresponding to the indexindicated by the SPS PDSCH release PDCCH. In order to manage a pluralityof SPS PDSCH reception configurations, the base station may group one ora plurality of SPS PDSCH reception configurations into one group. Ineach SPS PDSCH reception configuration, an SPS PDSCH group index may beconfigured to distinguish a group including a corresponding SPS PDSCHreception configuration. In each of the plurality of SPS PDSCH receptionconfigurations grouped into one group, an index of the same SPS PDSCHgroup is set. When the base station intends to release all SPS PDSCHreceptions included in the SPS PDSCH group, the base station mayindicate the index of the SPS PDSCH group in the SPS PDSCH releasePDCCH. When the UE is configured to receive a plurality of SPS PDSCHs, amethod of the base station releasing SPS PDSCH reception and a method oftransmitting a HARQ-ACK for a PDCCH for releasing a plurality of SPSPDSCHs may be problematic.

The index of the SPS PDSCH group may be indicated with a maximum of 4bits. The base station may insert the index of the SPS PDSCH group inthe HARQ process number field of the SPS PDSCH release PDCCH. The UE mayobtain the index of the SPS PDSCH group from the HARQ process numberfield of the SPS PDSCH release PDCCH, and determine that reception ofthe SPS PDSCH corresponding to the obtained SPS PDSCH group index hasbeen released. In this case, the UE may not receive the released SPSPDSCH. The HARQ process number field should be able to indicate themaximum value of the index of the SPS PDSCH group. Therefore, the sizeof the HARQ process number field may be determined through the followingembodiments. The number of bits in the HARQ process number field may beequal to ceil(log 2(max{# of HARQ process, # of group index for SPSPDSCH})). In this case, # of HARQ process is the number of HARQprocesses configured for the UE, and # of group index for SPS PDSCH isthe number of indexes of the SPS PDSCH group configured for the UE. Inanother specific embodiment, when the number of bits in the HARQ processnumber field is smaller than ceil(log 2(# of group index)), in additionto the HARQ process number field, as many bits of other fields of theDCI as the number of bits corresponding to the difference in lengthbetween ceil(log 2(# of group index)) and the HARQ process number fieldmay be used to indicate the index of the SPS PDSCH group. In this case,the other field may be at least one of a frequency domain resourceallocation (FDRA) field, a TDRA field, a modulation and coding scheme(MCS) field, and a redundancy version (RV) field.

When the UE receives the SPS PDSCH release PDCCH that simultaneouslyreleases a plurality of SPS PDSCH reception configurations, the UE mayinsert a bit indicating HARQ-ACK for the SPS PDSCH release PDCCH to thelocation of HARQ-ACK for the corresponding SPS PDSCH in the semi-staticHARQ-ACK codebook in which the SPS PDSCH release HARQ-ACK for one of aplurality of SPS PDSCH reception configurations released by the PDCCH isincluded. For example, it is assumed that the UE receives the SPS PDSCHrelease PDCCH for simultaneously releasing the first SPS PDSCH and thesecond SPS PDSCH. The HARQ-ACK for the first SPS PDSCH is transmitted tothe x^(th) bit in the semi-static HARQ-ACK codebook, and the HARQ-ACKfor the second SPS PDSCH is transmitted to the y^(th) bit in thesemi-static HARQ-ACK codebook. The UE may insert a bit indicatingHARQ-ACK for the SPS PDSCH release PDCCH instead of the bit indicatingHARQ-ACK for the first SPS PDSCH in the x^(th) bit of the semi-staticHARQ-ACK codebook. Alternatively, the UE may insert a hit indicatingHARQ-ACK for the SPS PDSCH release PDCCH instead of the bit indicatingHARQ-ACK for the second SPS PDSCH in the y^(th) bit of the semi-staticHARQ-ACK codebook. In these embodiments, the UE may select the SPS PDSCHcorresponding to the HARQ-ACK position in which the HARQ-ACK for the SPSPDSCH release PDCCH is inserted based on the time resources allocated toeach of the plurality of SPS PDSCH reception configurations. The UE mayselect the SPS PDSCH corresponding to the HARQ-ACK position in which theHARQ-ACK for the SPS PDSCH release PDCCH is to be inserted based on theindexes of the plurality of SPS PDSCH reception configurations. At thistime, when the UE receives the SPS PDSCH release PDCCH thatsimultaneously releases the plurality of SPS PDSCH receptionconfigurations, the UE may transmit a bit indicating the HARQ-ACK forthe SPS PDSCH release PDCCH instead of the bit indicating the HARQ-ACKof the SPS PDSCH corresponding to the lowest index among the pluralityof SPS PDSCH reception configuration indices.

In another specific embodiment, when the UE receives an SPS PDSCHrelease PDCCH that simultaneously releases a plurality of SPS PDSCHreception configurations, the UE may insert a hit indicating HARQ-ACKfor the SPS PDSCH release PDCCH to the location of bits indicatingHARQ-ACK for the corresponding SPS PDSCH of a plurality of semi-staticHARQ-ACK codebooks in which a bit indicating HARQ-ACK for each of theplurality of SPS PDSCH reception configurations released by the SPSPDSCH release PDCCH is included. For example, it is assumed that the UEreceives the SPS PDSCH release PDCCH for simultaneously releasing thefirst SPS PDSCH and the second SPS PDSCH. The HARQ-ACK for the first SPSPDSCH is transmitted to the x^(th) bit in the semi-static HARQ-ACKcodebook, and the HARQ-ACK for the second SPS PDSCH is transmitted tothe y^(th) hit in the semi-static HARQ-ACK codebook. The UE inserts abit indicating HARQ-ACK for the SPS PDSCH release PDCCH instead of thebit indicating HARQ-ACK for the first SPS PDSCH in the x^(th) bit of thesemi-static HARQ-ACK codebook, and inserts a bit indicating HARQ-ACK forthe SPS PDSCH release PDCCH instead of the bit indicating HARQ-ACK forthe second SPS PDSCH in the y^(th) bit of the semi-static HARQ-ACKcodebook.

Like the transmission of the SPS PDSCH, there is a configured grant (CG)PUSCH transmission scheduled for uplink transmission through semi-staticscheduling. The base station may release the CG PUSCH set to the UE bytransmitting the CG PUSCH release PDCCH. The CG PUSCH release PDCCH maybe scrambled with CS-RNTI. When the UE receives the CG PUSCH releasePDCCH, the UE releases the CG PUSCH corresponding to the index indicatedby the CG PUSCH release PUCCH. In order to manage a plurality of CGPUSCHs, the base station may designate a plurality of CG PUSCHs as onegroup.

The index of the CG PUSCH group may be indicated with a maximum of 4bits. The base station may insert the index of the CG PDSCH group intothe field of the DCI used to indicate the index of the SPS PDSCH group.The base station may insert the index of the CG PUSCH group into theHARQ process number field of the CG PUSCH release PDCCH. The UE mayobtain the index of the CG PUSCH group from the HARQ process numberfield of the field of the CG PUSCH release PDCCH, and determine that theCG PUSCH corresponding to the obtained CG PUSCH group index is released.At this time, the UE may stop transmitting the released CG PUSCH. TheHARQ process number field should be able to indicate the maximum valueof the index of the CG PDSCH group. Therefore, the size of the HARQprocess number field may be determined through the followingembodiments. The number of bits in the HARQ process number field may beequal to ceil (log 2(max{# of HARQ process, # of group index for CGPUSCH})). In this case, # of HARQ process is the number of HARQprocesses configured in the UE, and # of group index for CG PUSCH is thenumber of indexes of CG PUSCH groups configured in the UE. In anotherspecific embodiment, when the number of bits in the HARQ process numberfield is less than ceil (log 2 (# of group index)), in addition to theHARQ process number field, as many bits of other fields of the DCI asthe number of bits corresponding to the difference in length of ceil(log 2 (# of group index)) and the HARQ process number field may be usedto indicate the index of the CG PUSCH group. In this case, the otherfield may be at least one of a frequency domain resource allocation(FDRA) field, a TDRA field, a modulation and coding scheme (MCS) field,and a redundancy version (RV) field. In addition, the number of bits inthe HARQ process number field may be ceil(log 2(max{# of HARQ process, #of group index for CG PUSCH, # of group index for SPS PDSCH})). Thenumber of bits in the HARQ process number field may be determined basedon a maximum value among the number of HARQ processes, the number ofindexes of the CG PUSCH group, and the number of indexes of the SPSPDSCH group.

In the above-described embodiments, when the SPS PDSCH is configured, amethod for transmitting the HARQ-ACK for the SPS PDSCH release PDCCH bythe UE using a semi-static HARQ-ACK codebook has been described.Hereinafter, a method of transmitting the HARQ-ACK for the SPS PDSCHrelease PDCCH by the UE using the dynamic HARQ-ACK codebook will bedescribed.

As described above, the UE may determine the size of the dynamicHARQ-ACK codebook and the location of the HARQ-ACK for a specific signalor channel in the dynamic HARQ-ACK codebook using counter-DAI andtotal-DAI of the PDCCH scheduling the PDSCH. When the SPS PDSCH isactivated through the SPS PDSCH activation PDCCH, there is no DCIscheduling the SPS PDSCH. Therefore, the UE cannot determine the size ofthe dynamic HARQ-ACK codebook and the location of the HARQ-ACK in thedynamic HARQ-ACK codebook using the counter-DAI and total-DAI of thePDCCH. Therefore, when the SPS PDSCH is configured, the UE may add a1-bit HARQ-ACK indicating whether the SPS PDSCH is successfully receivedin the dynamic HARQ-ACK codebook. Specifically, the UE may add 1 bitindicating HARQ-ACK for whether the SPS PDSCH is successfully receivedat the end of the dynamic HARQ-ACK codebook. When the SPS PDSCH is notconfigured, the UE does not need to add a 1-bit HARQ-ACK for success inreception of the SPS PDSCH to the dynamic HARQ-ACK codebook. In thisembodiment, when the SPS PDSCH is configured, uplink control informationto be transmitted by the UE increases. Accordingly, the coverage of theuplink control channel (PUCCH) is reduced. This embodiment may beequally applied even when a plurality of SPS PDSCHs are configured inthe UE. Therefore, it is necessary to define a location in whichHARQ-ACK for each of a plurality of SPS PDSCHs is inserted into theHARQ-ACK codebook.

The location of the HARQ-ACK for each of the plurality of SPS PDSCHs inthe dynamic HARQ-ACK codebook may be determined based on the timeresource in which each of the plurality of SPS PDSCHs is received.Specifically, the UE may insert a time resource in which each of theplurality of SPS PDSCHs is received in the dynamic HARQ-ACK codebook,based on the received time resource. The UE may determine a locationbetween HARQ-ACKs for each of the plurality of SPS PDSCHs having thesame index, based on the time resource in which each of the plurality ofSPS PDSCHs is received. In a specific embodiment, when the UE determinesthe location of the HARQ-ACK information bit of the SPS PDSCH in thedynamic HARQ-ACK codebook, the UE may insert the HARQ-ACK for the SPSPDSCH received relatively earlier than the HARQ-ACK for the SPS PDSCHreceived relatively later in front of the dynamic HARQ-ACK codebook. Inanother specific embodiment, the UE may insert a HARQ-ACK for the SPSPDSCH received relatively later in front of the HARQ-ACK for the SPSPDSCH received relatively earlier. In this case, the UE may determinethat the SPS PDSCH preceded by the start symbol among the plurality ofSPS PDSCHs has been received first. In addition, when the start symbolsof the plurality of PDSCHs are the same, the UE may determine that theSPS PDSCH of which the last symbol precedes among the plurality of SPSPDSCHs having the same start symbol has been received first. When thelocation of the start symbol of the plurality of SPS PDSCHs is the sameand the location of the last symbol is also the same, the UE maydetermine the location between HARQ-ACKs for each of the plurality ofSPS PDSCHs, based on the frequency domain resource allocation of each ofthe plurality of SPS PDSCHs. Specifically, the UE may determine alocation between HARQ-ACKs for each of the plurality of SPS PDSCHs,based on the lowest PRB of each of the plurality of SPS PDSCHs. When thelocation of the start symbol of the plurality of SPS PDSCHs is the sameand the location of the last symbol is also the same, the UE maydetermine a position between HARQ-ACKs for each of the plurality of SPSPDSCHs in the dynamic HARQ-ACK codebook, based on the HARQ-ACK processnumber of each of the plurality of SPS PDSCHs.

FIG. 16 illustrates a case where a plurality of bits indicating HARQ-ACKfor each of a plurality of SPS PDSCHs having the same index are includedin the dynamic HARQ-ACK codebook together according to an embodiment ofthe present disclosure.

In the dynamic HARQ-ACK codebook, the location of the HARQ-ACK withrespect to whether the reception of each of the plurality of SPS PDSCHsis successful may be determined based on the index of each of theplurality of SPS PDSCHs. Specifically, the UE may insert HARQ-ACK foreach of the plurality of SPS PDSCHs into the dynamic HARQ-ACK codebookin ascending order of the indexes of each of the plurality of SPSPDSCHs. When determining the position of a bit in the dynamic HARQ-ACKcodebook, the UE may place an SPS PDSCH having a relatively low indexamong a plurality of SPS PDSCHs in front of the SPS PDSCH having arelatively high index. In another specific embodiment, the UE may insertHARQ-ACKs for each of the plurality of SPS PDSCHs into the dynamicHARQ-ACK codebook in descending order of the indexes of each of theplurality of SPS PDSCHs. When determining the position of a bit in thedynamic HARQ-ACK codebook, the UE may insert an SPS PDSCH having arelatively high index among a plurality of SPS PDSCHs in front of theSPS PDSCH having a relatively low index. However, in this embodiment,there may be a problem when a plurality of SPS PDSCHs in which HARQ-ACKis transmitted by one HARQ-ACK codebook have the same index.Specifically, reception of a plurality of SPS PDSCHs configured by thesame SPS PDSCH activation PDCCH may be problematic. For example, assumethat a subcarrier spacing of a DL cell is 30 KHz and a subcarrierspacing of a UL cell is 15 KHz. In the embodiment of FIG. 16 , the SPSPDSCH having a period of 1 slot is configured in a DL cell, and K1=1 isindicated as a HARQ-ACK time point indicating the number of slotsbetween the SPS PDSCH and the PUCCH through which HARQ-ACK istransmitted. When the SPS PDSCH configured in each of the 2n^(th) slotand the 2n+1^(th) slot of the DL cell is received, the UE transmitsHARQ-ACK on whether the reception of the SPS PDSCH configured in each ofthe 2n^(th) slot and the 2n+1^(th) slot of the DL cell in then+K1=n+1^(th) slot of the UL cell, and the indexes of the two SPS PDSCHsthrough which the UE transmits the HARQ-ACK are the same. This isbecause the two SPS PDSCHs to which the UE transmits the HARQ-ACK areSPS PDSCHs activated with one SPS PDSCH-activation PDCCH. In this case,the UE cannot determine the positions of bits indicating HARQ-ACK foreach of the plurality of SPS PDSCHs in the dynamic HARQ-ACK codebook,based only on the index of the SPS PDSCH.

The location of the HARQ-ACK for each of the plurality of SPS PDSCHs inthe dynamic HARQ-ACK codebook may be determined based on the index ofeach of the plurality of SPS PDSCHs and the time resource in which eachof the plurality of SPS PDSCHs is received. Specifically, the UE mayinsert HARQ-ACK for each of the plurality of SPS PDSCHs into the dynamicHARQ-ACK codebook, based on the index of each of the plurality of SPSPDSCHs and the time resource in which each of the plurality of SPSPDSCHs is received. First, the UE may determine the location of theHARQ-ACK for each of the plurality of SPS PDSCHs, based on the index ofeach of the plurality of SPS PDSCHs. A method of determining thelocation of the HARQ-ACK for each of the plurality of SPS PDSCHs, basedon the indexes of each of the plurality of SPS PDSCHs may be the same asin the above-described embodiments. When the indexes of the plurality ofSPS PDSCHs are the same, the UE may determine a location betweenHARQ-ACKs for each of the plurality of SPS PDSCHs having the same index,based on the time resources in which each of the plurality of SPS PDSCHsis received. In a specific embodiment, when the indexes of the pluralityof SPS PDSCHs are the same, the UE may insert the HARQ-ACK for the SPSPDSCH received relatively earlier ahead of the HARQ-ACK for the SPSPDSCH received relatively later in front of the dynamic HARQ-ACKcodebook. In another specific embodiment, when the indexes of aplurality of SPS PDSCHs arc the same, the UE may insert a HARQ-ACK forthe SPS PDSCH received relatively later ahead of the HARQ-ACK for theSPS PDSCH received earlier. In this case, the UE may determine that theSPS PDSCH preceded by the start symbol among the plurality of SPS PDSCHshas been received first. In addition, when the start symbols of theplurality of PDSCHs are the same, the UE may determine that the SPSPDSCH of which the last symbol precedes among the plurality of SPSPDSCHs having the same start symbol has been received first. When theindexes of the plurality of SPS PDSCHs are the same, the position of thestart symbol is the same, and the position of the last symbol is alsothe same, the UE may determine a location between HARQ-ACKs for each ofthe plurality of SPS PDSCHs, based on the frequency domain resourceallocation of each of the plurality of SPS PDSCHs. Specifically, the UEmay determine a location between HARQ-ACKs for each of the plurality ofSPS PDSCHs, based on the lowest PRB of each of the plurality of SPSPDSCHs. When the indexes of the plurality of SPS PDSCHs are the same,the position of the start symbol is the same, and the position of thelast symbol is also the same, the UE may determine a position betweenHARQ-ACKs for each of the plurality of SPS PDSCHs in the dynamicHARQ-ACK codebook, based on the HARQ-ACK process number of each of theplurality of SPS PDSCHs.

The location of the HARQ-ACK for each of the plurality of SPS PDSCHs inthe dynamic HARQ-ACK codebook may be determined based on the HARQprocess number of each of the plurality of SPS PDSCHs. Specifically, theUE may insert HARQ-ACK for each of the plurality of SPS PDSCHs into thedynamic HARQ-ACK codebook in ascending order of the HARQ process numberof each of the plurality of SPS PDSCHs. The UE may insert the SPS PDSCHhaving a relatively low HARQ process number among the plurality of SPSPDSCHs in front of the dynamic HARQ-ACK codebook ahead of the SPS PDSCHhaving a relatively high HARQ process number. In another specificembodiment, the UE may insert HARQ-ACK for each of the plurality of SPSPDSCHs into the dynamic HARQ-ACK codebook in descending order of theHARQ process number of each of the plurality of SPS PDSCHs. The UE mayinsert the SPS PDSCH having a relatively high HARQ process number amongthe plurality of SPS PDSCHs in front of the dynamic HARQ-ACK codebookahead of the SPS PDSCH having a relatively low HARQ process number. Whena plurality of different SPS PDSCHs have one HARQ process number, the UEcannot generate HARQ-ACKs for the plurality of SPS PDSCHs. This isbecause one soft-combiner of the UE is allocated to one HARQ processnumber. When a plurality of SPS PDSCHs correspond to one HARQ processnumber, the UE may allocate one bit to a dynamic HARQ-ACK codebook of aplurality of SPS PDSCHs corresponding to one HARQ process number. Inanother specific embodiment, when a plurality of SPS PDSCHs correspondto one HARQ process number, the UE may determine a position betweenHARQ-ACKs for each of the plurality of SPS PDSCHs in the dynamicHARQ-ACK codebook, based on the time domain information of the SPSPDSCH. In addition, when a plurality of SPS PDSCHs correspond to oneHARQ process number, the UE may determine a position between HARQ-ACKsfor each of the plurality of SPS PDSCHs in the dynamic HARQ-ACKcodebook, based on the index of the SPS PDSCH.

The HARQ process number may be allocated according to the followingequation.

HARQ Process number=[floor(CURRENT_slot×10/(numberOfSlotsPerFrame×periodicity))┘ modulonrofHARQ-Processes

The HARQ Process number indicates the HARQ process number,CURRENT_slot=[(SFN×numberOfSlotsPerFrame)+slot number in the frame], andthe periodicity indicates the period of SPS PDSCH receptionconfiguration. nrofHARQ-Process represents the number of HARQ processnumbers that can be used by the SPS PDSCH reception configuration. Theperiodicity and nrofHARQ-Process are set from the upper layer.numberOfSlotsPerFrame represents the number of slots per frame.numberOfSlotsPerFrame is determined according to the subcarrierinterval. If the subcarrier interval is 15 kHz, numberOfSlotsPerFrame is10, if the subcarrier interval is 30 kHz, numberOfSlotsPerFrame is 20,if the subcarrier interval is 60 kHz, numberOfSlotsPerFrame is 40, andif the subcarrier interval is 120 kHz, numberOfSlotsPerFrame is 80. slotnumber in the frame represents the number of slots in the frame. Inaddition, SFN represents a system frame number. floor(x) represents themaximum value among integers less than or equal to x. x modulo yrepresents the remaining value when x is divided by y. When the HARQprocess number is allocated according to the above equation, asdescribed above, one HARQ process number may be allocated to differentSPS PDSCHs. In another specific embodiment, the base station mayallocate the HARQ process number to the SPS PDSCH so that different SPSPDSCHs always correspond to different HARQ process numbers.Specifically, the base station may allocate the HARQ process numberaccording to the following equation.

HARQ Process number=[[floor(CURRENT_slot×10/(numberOfSlotsPerFrame×periodicity))] modulonrofHARQ-Processes]+Offset

By adding the offset to the above-described equation, the base stationadjusts the offset to allocate the HARQ process number to the SPS PDSCHso that different SPS PDSCHs always correspond to different HARQ processnumbers. Specifically, the HARQ process may be assigned Offset,Offset+1, . . . , Offset+nrofHARQ-Process−1 to the number.

The location of the HARQ-ACK for each of the plurality of SPS PDSCHs inthe dynamic HARQ-ACK codebook may be determined based on a cell indexcorresponding to each of the plurality of SPS PDSCHs. The UE may insertHARQ-ACK for each of the plurality of SPS PDSCHs into the dynamicHARQ-ACK codebook, based on a cell index corresponding to each of theplurality of SPS PDSCHs. Specifically, the UE may insert HARQ-ACK for anSPS PDSCH corresponding to a relatively low cell index among a pluralityof dynamic SPS PDSCHs to the front of the dynamic HARQ-ACK codebook, andmay insert a HARQ-ACK for an SPS PDSCH corresponding to a relativelyhigh cell index among a plurality of SPS PDSCHs to the back of thedynamic HARQ-ACK codebook.

The dynamic grant (DG) PDSCH is a PDSCH scheduled by dynamic schedulingdescribed above. Specifically, the DG PDSCH is the PDSCH scheduled byPDCCH. When the SPS PDSCH-scheduled resource and the DG PDSCH-scheduledresource overlap, there is a problem in how the UE generates theHARQ-ACK codebook.

FIG. 17 illustrates a method for a UE to generate a dynamic HARQ-ACKcodebook when an SPS PDSCH-scheduled resource and a DG PDSCH-scheduledresource overlap according to an embodiment of the present disclosure.

The DG PDSCH is a PDSCH scheduled by dynamic scheduling described above.Specifically, the DG PDSCH is the PDSCH scheduled by PDCCH. When the SPSPDSCH-scheduled resource and the DG PDSCH-scheduled resource overlap,the UE may assign a higher priority to the DG PDSCH than to the SPSPDSCH. Specifically, when the resources scheduled for the SPS PDSCH andthe resources scheduled for the DG PDSCH overlap, the UE may receive theDG PDSCH without receiving the SPS PDSCH. In a specific embodiment, theUE may receive the PDSCH, based on the PDCCH scheduling the DG PDSCH. Inaddition, the UE may generate a dynamic HARQ-ACK codebook, based on thecounter-DAI and total-DAI of the PDCCH scheduling the DG PDSCH. In thiscase, the UE may transmit HARQ-ACK for the SPS PDSCH according to theabove-described embodiments separately from the dynamic HARQ-ACKcodebook generated based on the counter-DAI and the total-DAI of thePDCCH scheduling the DG PDSCH even if the UE does not receive the SPSPDSCH. Therefore, even though it is obvious that the UE does not receivethe SPS PDSCH, the UE unnecessarily transmits the HARQ-ACK for the SPSPDSCH to the base station.

When the SPS PDSCH-scheduled resource and the DG PDSCH-scheduledresource overlap, the UE may not generate a separate bit for a bitindicating HARQ-ACK on whether or not the DG PDSCH is successfullyreceived in the dynamic HARQ-ACK codebook, but may insert a bitindicating HARQ-ACK for whether the DG PDSCH is successfully received atthe position of the HARQ-ACK information bit of the overlapped SPSPDSCH. In this case, a bit indicating HARQ-ACK on whether or not theoverlapped SPS PDSCH is successfully received may not be included in thedynamic codebook. When there are a plurality of SPS PDSCHs overlappingwith the time-frequency resource in which the DG PDSCH is scheduled, theUE may select one SPS PDSCH from among a plurality of SPS PDSCHs, andmay insert a bit indicating HARQ-ACK for the DG PDSCH at a position of abit indicating HARQ-ACK of the SPS PDSCH selected from the dynamicHARQ-ACK codebook. In this case, the UE may select one SPS PDSCH fromamong the plurality of SPS PDSCHs, based on the time frequency resourcethrough which each of the plurality of SPS PDSCHs is transmitted.Specifically, the UE may select the SPS PDSCH that is most advanced intime among the plurality of SPS PDSCHs. In another specific embodiment,the UE may select one SPS PDSCH from among a plurality of SPS PDSCHs,based on the indexes of each of the plurality of SPS PDSCHs. In anotherspecific embodiment, the UE may select one SPS PDSCH from among aplurality of SPS PDSCHs, based on a HARQ process number corresponding toeach of the plurality of SPS PDSCHs. When the SPS PDSCH-scheduledresource and the DG PDSCH-scheduled resource do not overlap, the UE maygenerate a dynamic HARQ-ACK codebook, based on the counter-DAI andtotal-DAI of the PDCCH scheduling the DG PDSCH to the base station.

When there are a plurality of SPS PDSCHs overlapping with thetime-frequency resource in which the DG PDSCH is scheduled, the UE maydetermine the type of the DG PDSCH and may determine a method oftransmitting the HARQ-ACK for the DG PDSCH according to the type. Whenthe DG PDSCH is determined as the first type, the UE may generate adynamic HARQ-ACK codebook, based on the counter-DAI and total-DAI of thePDCCH scheduling the DG PDSCH. When the DG PDSCH is determined as thesecond type, the UE may transmit a bit indicating HARQ-ACK for DG PDSCHto the base station instead of a bit indicating HARQ-ACK for SPS PDSCHin the HARQ-ACK codebook scheduled to include HARQ-ACK for one of aplurality of SPS PDSCHs. In this case, a method of determining whetherto insert a bit indicating a HARQ-ACK for a DG PDSCH into a HARQ-ACKcodebook for any SPS PDSCH among a plurality of SPS PDSCHs may be thesame as in the above-described embodiments. Specifically, when the DGPDSCH is of the first type, the UE may generate a first sub-HARQ-ACKcodebook, based on the PDCCH scheduling the DG PDSCH. In addition, whenthe DG PDSCH is of the second type, the UE may generate a secondsub-HARQ-ACK codebook in which bits indicating HARQ-ACK for DG PDSCH areinserted instead of bits indicating HARQ-ACK for SPS PDSCH in theHARQ-ACK codebook scheduled to include HARQ-ACK for one of a pluralityof SPS PDSCHs. The UE may generate a dynamic HARQ-ACK codebook bycombining the first sub-HARQ-ACK codebook and the second sub-HARQ-ACKcodebook, and transmit the generated dynamic HARQ-ACK codebook to thebase station.

In addition, the UE may determine the type of the DG PDSCH, based on thetotal-DAI value and the counter-DAI value of the DCI of the PDCCHscheduling the DG PDSCH. Specifically, when the total-DAI of the DCI ofthe PDCCH scheduling the DG PDSCH is the first value and the counter-DAIvalue is the second value, the UE may determine the DG PDSCH as thesecond type. In other cases, the UE may determine the DG PDSCH as thefirst type. In this case, the first value and the second value may bethe same value. For example, both the first value and the second valuemay be 4. In another embodiment, the UE may determine the type of the DGPDSCH, based on the value of the counter-DAI of the DCI of the PDCCHscheduling the DG PDSCH. Specifically, when the counter-DAI value of theDCT of the PDCCH scheduling the DG PDSCH is the first value, the UE maydetermine the DG PDSCH as the second type. In other cases, the UE maydetermine the DG PDSCH as the first type. In this case, the first valuemay be 4.

In the embodiment of FIG. 17 , three SPS PDSCHs are configured. Thefirst SPS PDSCH (SPS PDSCH#0) is allocated to the first symbol 0 and thesecond symbol 1 of the slot. The second SPS PDSCH (SPS PDSCH#1) isallocated to the third symbol 2 and the fourth symbol 3 of the slot. Thethird SPS PDSCH (SPS PDSCH#3) is allocated to the fifth symbol 4, thesixth symbol 5, the seventh symbol 6 and the eighth symbol 7 of theslot. The UE receives 4 PDCCHs. The first PDCCH schedules the firstDG-PDSCH (DG PDSCH#0) in the second symbol 1, the third symbol 2, thefourth symbol 3, and the fifth symbol 4 of the slot. The second PDCCHschedules a second DG-PDSCH (DG PDSCH#1) in the sixth symbol 5 and theseventh symbol 6 of the slot. The third PDCCH schedules a third DG-PDSCH(DG PDSCH#3) in the eighth symbol 7 and the eleventh symbol 8 of theslot. The fourth PDCCH schedules a fourth DG-PDSCH (DG PDSCH#3) in theeleventh symbol 10, the twelfth symbol 11, the thirteenth symbol 12, andthe fourteenth symbol 13 of the slot. The value of the counter-DAI ofthe first PDCCH is 4, the value of the counter-DAI of the second PDCCHis 4, the value of counter-DAI of the third PDCCH is 1, and the value ofcounter-DAI of the fourth PDCCH is 2. In the embodiment of FIG. 16 ,when the value of the counter-DAI of the DCI of the PDCCH is 4, the UEdetermines the DG PDSCH as the second type. In this case, when theDG-PDSCH is of the second type, the UE may insert a bit indicating theHARQ-ACK for the DG PDSCH in the HARQ-ACK codebook for the SPS PDSCHthat is temporally most advanced among the plurality of SPS PDSCHs.

The counter-DAI value of the third PDCCH and the counter-DAI value ofthe fourth PDCCH are not 4. Therefore, the UE determines the location ofthe HARQ-ACK for the third DG-PDSCH (DG PDSCH#2) in the firstsub-HARQ-ACK codebook, based on the counter-DAI and the total-DAI of thethird PDCCH, and inserts a bit indicating the HARQ-ACK for the thirdDG-PDSCH (DG PDSCH#2) at the position b(0) determined in the firstsub-HARQ-ACK codebook. In addition, the UE determines the location ofthe HARQ-ACK for the fourth DG-PDSCH (DG PDSCH#3) in the firstsub-HARQ-ACK codebook, based on the counter-DAI and the total-DAI of thefourth PDCCH, and inserts a bit indicating the HARQ-ACK for the fourthDG-PDSCH (DG PDSCH#3) at the position b(1) determined in the firstsub-HARQ-ACK codebook. Since the value of counter-DAI of the first PDCCHis 4, the UE inserts a hit indicating HARQ-ACK for the first DG-PDSCH(DG PDSCH#1) instead of a bit indicating HARQ-ACK for the first SPSPDSCH (SPS PDSCH#0) C(0) in the second sub-HARQ-ACK codebook. Since thevalue of the Counter-DAI of the second PDCCH is also 4, the UE inserts abit indicating HARQ-ACK for the second DG-PDSCH (DG PDSCH#1) instead ofa bit indicating HARQ-ACK for the second SPS PDSCH (SPS PDSCH#1) C(1) inthe second sub-HARQ-ACK codebook. The UE generates a HARQ-ACK codebookby combining the first sub-HARQ-ACK codebook and the second sub-HARQ-ACKcodebook, and transmits the generated HARQ-ACK codebook to the basestation.

As described above, two or more HARQ-ACKs corresponding to one HARQprocess cannot be transmitted in one HARQ-ACK codebook. Therefore, whenthere is an SPS PDSCH corresponding to the same HARQ process number asthe HARQ process number of the DG PDSCH, the UE may insert a bitindicating HARQ-ACK for the DG PDSCH instead of a bit indicatingHARQ-ACK for the SPS PDSCH in the HARQ-ACK codebook in which theHARQ-ACK for the SPS PDSCH corresponding to the same HARQ process numberas the HARQ process number of the DG PDSCH is to be transmitted.

In the above-described embodiments, the physical data channel mayinclude a PDSCH or a PUSCH. In addition, the physical control channelmay include a PDCCH or PUCCH. In addition, in the embodiment describedby taking PUSCH, PDCCH, PUCCH, and PDCCH as an example, different typesof data channels and control channels may be applied.

Although the method and system of the present disclosure have beendescribed in connection with specific embodiments, some or all of theircomponents or operations may be implemented using a computing systemhaving a general-purpose hardware architecture.

The above description of the present disclosure is for illustrativepurposes only, and those of ordinary skill in the art to which thepresent disclosure pertains will be able to understand that otherspecific forms can be easily modified without changing the technicalspirit or essential features of the present disclosure. Therefore, itshould be understood that the embodiments described above areillustrative and non-limiting in all respects. For example, eachcomponent described as a single type may be implemented in a distributedmanner, and similarly, components described as being distributed mayalso be implemented in a combined form.

The scope of the present disclosure is indicated by the claims to hedescribed later rather than the detailed description, and all changes ormodified forms derived from the meaning and scope of the claims andtheir equivalent concepts should be construed as being included in thescope of the present disclosure.

1-20. (canceled)
 21. A user equipment in a 3^(rd) generation partnershipproject (3GPP)-based wireless communication system, the user equipmentcomprising: a communication module; and a processor configured tocontrol the communication module, wherein the processor is configuredto: receive a plurality of physical downlink control channels (PDCCHs),wherein each PDCCH is associated with a respective reception time andcell index; and transmit a hybrid automatic repeat requestacknowledgement (HARQ-ACK) codebook on a physical uplink control channel(PUCCH) resource associated with a last PDCCH among the plurality of thePDCCHs, wherein the plurality of the PDCCHs is ordered based on areception time and cell index associated with each of the plurality ofthe PDCCHs, and wherein, among the plurality of PDCCHs, at least twoPDCCHs associated with a same reception time and cell index are orderedfurther based on a control resource set (CORESET) index associated witheach of the at least two PDCCHs.
 22. The user equipment of claim 21,wherein the same reception time and the same cell index includes a samelatest reception time and a same highest cell index, and the at leasttwo PDCCHs are ordered in an ascending order of CORESET indexes.
 23. Theuser equipment of claim 21, wherein the reception time is determinedbased on a starting symbol of each PDCCH.
 24. The user equipment ofclaim 21, wherein each of the plurality of PDCCHs schedules a respectivephysical downlink shared channel (PDSCH).
 25. The user equipment ofclaim 21, wherein counter downlink assignment indexes (c-DAIs) in theplurality of PDCCHs are ordered based on the reception time and cellindex associated with each PDCCH, and wherein, at least two c-DAIs inthe at least two PDCCHs are ordered further based on CORESET indexesassociated with the at least two PDCCHs.
 26. A method for use by a userequipment in a 3rd generation partnership project (3GPP)-based wirelesscommunication system, the method comprising: receiving a plurality ofphysical downlink control channels (PDCCHs), wherein each PDCCH isassociated with a respective reception time and cell index; andtransmitting a hybrid automatic repeat request acknowledgement(HARQ-ACK) codebook on a physical uplink control channel (PUCCH)resource associated with a last PDCCH among the plurality of the PDCCHs,wherein the plurality of the PDCCHs is ordered based on a reception timeand cell index associated with each of the plurality of the PDCCHs, andwherein, among the plurality of PDCCHs, at least two PDCCHs associatedwith a same reception time and cell index are ordered further based on acontrol resource set (CORESET) index associated with each of the atleast two PDCCHs.
 27. The method of claim 26, wherein the same receptiontime and the same cell index includes a same latest reception time and asame highest cell index, and the at least two PDCCHs are ordered in anascending order of CORESET indexes.
 28. The method of claim 26, whereinthe reception time is determined based on a starting symbol of eachPDCCH.
 29. The method of claim 26, wherein each of the plurality ofPDCCHs schedules a respective physical downlink shared channel (PDSCH).30. The method of claim 26, wherein counter downlink assignment indexes(c-DAIs) in the plurality of PDCCHs are ordered based on the receptiontime and cell index associated with each PDCCH, and wherein, at leasttwo c-DAIs in the at least two PDCCHs are ordered further based onCORESET indexes associated with the at least two PDCCHs.
 31. A basestation in a 3^(rd) generation partnership project (3GPP)-based wirelesscommunication system, the base station comprising: a communicationmodule; and a processor configured to control the communication module,wherein the processor is configured to: transmit a plurality of physicaldownlink control channels (PDCCHs), wherein each PDCCH is associatedwith a respective transmission time and cell index; and receive a hybridautomatic repeat request acknowledgement (HARQ-ACK) codebook on aphysical uplink control channel (PUCCH) resource associated with a lastPDCCH among the plurality of the PDCCHs, wherein the plurality of thePDCCHs is ordered based on a transmission time and cell index associatedwith each of the plurality of the PDCCHs, and wherein, among theplurality of PDCCHs, at least two PDCCHs associated with a sametransmission time and cell index are ordered further based on a controlresource set (CORESET) index associated with each of the at least twoPDCCHs.
 32. The base station of claim 31, wherein the same transmissiontime and the same cell index includes a same latest transmission timeand a same highest cell index, and the at least two PDCCHs are orderedin an ascending order of CORESET indexes.
 33. The base station of claim31, wherein the transmission time is determined based on a startingsymbol of each PDCCH.
 34. The base station of claim 31, wherein each ofthe plurality of PDCCHs schedules a respective physical downlink sharedchannel (PDSCH).
 35. The base station of claim 31, wherein counterdownlink assignment indexes (c-DAIs) in the plurality of PDCCHs areordered based on the transmission time and cell index associated witheach PDCCH, and wherein, at least two c-DAIs in the at least two PDCCHsare ordered further based on CORESET indexes associated with the atleast two PDCCHs.
 36. A method for use by a base station in a 3^(rd)generation partnership project (3GPP)-based wireless communicationsystem, the method comprising: transmitting a plurality of physicaldownlink control channels (PDCCHs), wherein each PDCCH is associatedwith a respective transmission time and cell index; and receiving ahybrid automatic repeat request acknowledgement (HARQ-ACK) codebook on aphysical uplink control channel (PUCCH) resource associated with a lastPDCCH among the plurality of the PDCCHs, wherein the plurality of thePDCCHs is ordered based on a transmission time and cell index associatedwith each of the plurality of the PDCCHs, and wherein, among theplurality of PDCCHs, at least two PDCCHs associated with a sametransmission time and cell index are ordered further based on a controlresource set (CORESET) index associated with each of the at least twoPDCCHs.
 37. The method of claim 36, wherein the same transmission timeand the same cell index includes a same latest transmission time and asame highest cell index, and the at least two PDCCHs are ordered in anascending order of CORESET indexes.
 38. The method of claim 36, whereinthe transmission time is determined based on a starting symbol of eachPDCCH.
 39. The method of claim 36, wherein each of the plurality ofPDCCHs schedules a respective physical downlink shared channel (PDSCH).40. The method of claim 36, wherein counter downlink assignment indexes(c-DAIs) in the plurality of PDCCHs are ordered based on thetransmission time and cell index associated with each PDCCH, andwherein, at least two c-DAIs in the at least two PDCCHs are orderedfurther based on CORESET indexes associated with the at least twoPDCCHs.